The 8 years of optimization didn't go into Wii U's hardware though, it went into the PS3 and 360 hardware, which are very different from Wii U. There has been little effort invested into optimizing to get the most out of Wii U's specific hardware.

Games like Trine 2 Director's Cut were able to push graphics that are by the admission of the devs beyond PS3/360 capacity. As well as being several (GPU) generations ahead of the PS3/360, Wii U's GPU also has DX10-11 features.

The lower RAM bandwidth is compensated for by having 32MB of high speed eDRAM to handle data that needs rapid access. This is more than 3 times as much eDRAM as the 360 had, and the PS3 had none at all.

Just this past month we saw the release of Art of Balance, which technically outdoes any previously released game on Wii U, and the same studio is looking to push the system even further with their next game.

The Wii U's hardware is based off the 360 hardware believe it or not.  GPU is based off of AMD tech much like the 360.  That old tech hasn't changed, the transisters are what they are.  The only thing is that the GPU was updated to take advantage of newer technologies.  But as I have mentioned though, the PS4 and Xbox One can barely handle that tech and they have far more powerful hardware.  My hunch is that Nintendo got something newer with enough grunt to handle old tech well with enough with some power to spare to save on costs.  Said power has to make up for the CPU though which brings the hardware back to square one and in line with the power envelope.  Same with the CPUs.  PowerPC is Power PC, that's not going to change and IBM had processors in the last 3 consoles, and even way back to the Gamecube.  No one is going to be able to do more with those outdated CPUs.  Bottom line, the engines are maxed and that includes what's in the Wii U.

Again, I never said the Wii U isn't more powerful, I said there's not much left, same goes for the ram.  32mb isn't enough for anything, you can't throw in 1 gig of data into 32 mb.  That's impossible.  It's why the Xbox One is currently having problems.  Which goes back to my analysis, they cheaped out on slower ram to save costs.  They put in a gig and edram to try to make up with that deficiency.  But the bottleneck puts it back in line with the PS3 and 360, and as ports have shown, is actually worse off.  

This game?

No, that's the Wii version. This game:

Subsurface scattering, physically based shading, 4k-8k textures, deferred rendering at 60fps. And that's a screen from an unfinished build.

Wii U is quite a bit different from the 360; CPUs may both be PowerPC based, but there's a world of difference between Xenon's Cell-based processor and Wii U's PPC750 based one. Code designed for the former won't transition well to the latter. Memory speed and layout also means Wii U engines need to be built more specifically around eDRAM management. For a machine of Wii U's strength, 32MB is more than adequate.

Ports performing worse on Wii U are because devs were building on 7-8 years of PS3/360 experience and almost none with Wii U. Also, because the games were built around PS3/360 they were not properly optimized to take advantage of Wii U's different hardware.

When devs actually leverage Wii U's advantages we get games like Trine 2 Director's Cut, which was confirmed by its devs to be beyond the abilities of PS3 and 360. Need for Speed is also an example of a Wii U port looking and running better on Nintendo's system.

When all the big third party engines are built around different hardware, and exclusives are mostly technologically conservative, it will take more than two years for a system's best graphics to emerge.

The Wii U's hardware is based off the 360 hardware believe it or not. 

I dont believe in the tooth fairy either. What you said is 100% false. The Wii U is an evolution of the Gamecube, just like the Xbox 360.

I have no idea what you're reading about that game, but there is no sub surface scattering in that game, nor can I see any signs for a deferred renderer.  To be fair, they may actually be using a deferred renderer, but there's a lack of local lighting.  4K texture would be no biggy if they could fit it in 1gig.  There's also not a that screen to be textured so I don't see how that can be called impressive.  It's like the nvidia head demo, none of their GPUs will be able to render a head like that in a game scenario.  But if its just one head its possible.  P.S. this is what sub-surface scattering is and you'll notice there's none of that there:

Look at all that back light.

Let me give you an analogy for memory architecture since what I said went over your head apparently.  Let's say you have 3 cars, your frame buffer, your anti-aliasing, and you have this HUGE tractor trailer as your third car.  We'll call him your textures.  Now magically, the truck can move just as fast as the cars.  BUT there are speed limits on the road.  Because of this speed limit, all 3 cars are reaching their destination really slowly.  So, after some thought, the city counselors, who we'll call Nintendo, decided that they need to build a highway for the cars, which we'll call eDram.  There's one catch though, there's only enough room to build a highway that only fits, two cars.  The frame buffer and anti-aliasing will be able to take this highway, but not Texture.  Texture's unfortunately way too big since they built the highway specifically to the width of the cars and not the truck.  Which means Texture has to always take the side route and always get to its destination (CPU/GPU) late.  I can't simplify this explanation any further as to why the eDram isn't going to help with performance in the Wii U's case and things would be far worse if they actually stuck with the less than 512(OS ate up space) gigs of ram from last gen.  The 1 gig is to bring performance up to the 512gb of last gen by caching more data.  This also doesn't work out too well in real world situations but the extra space is welcomed.

There's a difference between Cell and the other two prcessors, but that's because of the SPUs, which Toshiba designed.  The Xenon cores are actually based off the PPE from Cell.  Though, the PowerPC architecture is what it is, the assembly hasn't changed much and it took a really long time for them to get Power8 out the door.  The Power architecture in the Wii U is most likely based off of the old GC Power processor upgraded as much as possible to the 45nm processor node.  The low clock speed supports this (A tear down of the processor and OS dumps also help suppor this).  3 processors of old designs on the same die will be generating high heat, thus lower clock to keep thermals down.  Nintendo's engineers decided this to keep BC and costs down.  Looking at the older architecture, they can't get the clocks higher than they are.  So in a way, it is different from Xenon/Cell, in that it's older and worse.  I'll also remind you, since you're ignoring what I'm saying, Nintendo had AMD take one of their GPUs, something cheap but powerful enough to make up for the CPU.  Nintendo designed their entire console to give you last gen at a cheaper cost.  They also would have succeeded had they not made that tablet, but that discussion will be way off topic. 

Ports are performing worse because of the Wii U hardware not being up to task, nothing more.  You're assumption is that all the pros in the Wii U aren't negated by Nintendo cheaping out.  Which I already explained, and regurgitated here to you this.  

I also said that the Wii U does indeed have a better GPU than Xenos and RSX, it's also really hampered.  Whatever advantages it has are essentially negated.  Can you do a bit more with Trine 2?  Sure.  Trine is also a low poly, 2D spec'd game that doesn't look very good.  Hell there are games on the PS3 and 360 that look a hell of a lot better and do far more than the Wii U version of Trine is doing.  As far as the better textures in Need For Speed goes?  It damn well better, it has a full 512 extra megs of ram for games.   It also doesn't get as good looking as the PC version despite that.  As far as a more consistent framerate (Which still dips less than 30 FIY), is due to having a bit of muscle left over to spare after the GPU has to get violated by CPU work.  The better question is, why couldn't the Wii U render Need For Speed at a 100% locked framerate?  Better yet, why couldn't it reach 60fps or higher?  Answer is simple, there's just not that much power left over in the Wii U to take advantage of.  You say that Need For Speed was coded properly to use the Wii U, yet how much of a performance increase does it really have over the PS3/360 version?  The answer?  Not much.  Because there isn't much hidden power in the Wii U to tap.  Why is that?  Nintendo designed a machine to give you last gen at a cheaper cost.

The devs themselves confirmed it uses subsurface scattering: http://nintendoeverything.com/weekly-screenshot-art-of-balance-wii-u-2-marvelous-menu-screen/ 

And the devs of Trine 2 have gone on record saying the PS3 and 360 could not handle the Wii U version without downgrades: http://www.geek.com/games/ps3-360-cant-cope-with-trine-2-wii-u-graphics-1521231/

To max out a console, you need technically ambitious games designed specifically around the quirks of the hardware. Such efforts are virtually non-existent on Wii U because third parties devs aren't interested, and 1st party devs are technologically conservative. On Xbox/Playstation, you have devs pouring tens of millions of dollars into pushing the graphical envelope as far as they can. Nobody's doing that on Wii U, therefore its full potential isn't being tapped.

Unless the devs are mistaking bloom with sub surface scattering; they're talking out of their ass.  The only thing that "may" have it, is that clear thing.  Textures, lighting, scene scale, is all a joke.

Trine is FAR from being a technically good looking title.  It's a 2D platformer with simple models/textures and there are more far superior titles on the PS3 and 360.  But let's take a look at what wouldn't run on the PS3/360.  The "Goblin Menace" expansion.  I was taking a look at it just now and the only thing impressive is the lighting model.  Which from what I can tell is running on a deferred renderer to give you all those local lights.  Killzone 2 was one of the first games to use a deferred renderer, is capable of using far more local light sources that is present in Trine with a global illumination model going on to light the world (Which Trine does).  It does what Trine is doing, with far larger, more complex levels.  It has far more enemies on screen at the same time, and is one of the best textured titles on the PS2.  I'm not even going to mention the far more better looking and demanding titles since Killzone 2 released cause they make Trine 2 look like a PS2 game in comparison.  I'll believe that the devs weren't capable of porting their code as is (i.e. lazy/costs) and didn't want to figure out how to bring their code over. And as I said before, the Wii U is a bit more capable, but that's like saying the Xbox is more capable than the Gamecube.  To say the PS3 or 360 (Well the 360 might not) isn't capable of running that expansion with downgrades is as believable as Ubisoft saying the PS4 couldn't handle higher resolutions of Assassin's Creed Unity.

Lastly as I said, the Wii U isn't capable of much more than the PS3 or 360.  Is it more capable?  Of course.  It doesn't have the processing power behind it to actually give you something much better.  So you're stuck with very mature graphic engines that have spent the last 7 years being optimized(I.e. as good as it gets) ported to the Wii U.  P.S. stop ignoring all the technical aspects explaining the Wii U's deficiencies  that hinder its advantages.  I've explained it 3 times to you and your only counter argument are showing me subpar technical titles with devs talking out of their asses to make it look like their games are "amazing".  Cause you know, no devs have talked out of their asses hyping up their games and engines.  Find something that you can actually use, like a powerpoint presentation from devs, or a game that actually does something better (Which you won't be able to find).