It's not publishing that's the problem, it's developing for the system. Thee Wii U is now the only non x86 system on the market, which fragments the development for it.

That being said, I would be perfectly content with it, I'm mostly digital now anyway.

It's basically the architecture of the console. It's impossible to change now, since the Wii U uses a PowerPC CPU and to change the architecture you'd have to overhaul the CPU, which won't happen.

It is an hardware problem. X86 is the CPU core architecture, WiiU has PowerPC cores. It is impossible in any way to change that.

The CPU excuse doesn't fit, its their estimated ROI. For example we have the latest Resident Evil HD remake, only digital release, and the original remake was made on the Gamecube (PowerPC). Porting that to the WiiU should be a piece of cake, and then releasing via the eShop would make it all profits, but they aren't doing it, it isn't their focus; meanwhile 360 PowerPC, PS3 Cell, PS4/XB1 x86 and PC (x64?) are all getting ported. I'm sure it will even hit mobile.

I feel I should point out that the Wii, PS3, and Xbox 360 are all still on the market. So that excuse really doesn't fly.

And Wii, PS3, and 360 are all older consoles with already established fanbases, which easily covers the cost of porting. Not to mention, devs are slowly weening off those as well.

But your claim was that they were stopping support of Wii U because it's the only system that requires coding for that sort of CPU. Which is false. Until they cease development for the older consoles, you cannot assert that it's because of the CPU.

So if you have a PS4 game, but you want to port it to Wii U and XOne, how long would it take for both versions in comparison?

Im having a hard time imagining the difference.

No, but it is partially due to the CPU. The architecture combined with the low install base makes devs think twice about porting games. It is feasible to port to older consoles since they have such a high install base, not here though.

PS4 ---> Xbox One would take a short amount of time. Both have x86 CPUs, and have the same amount of cores. The game would be scaled to make up for the slightly weaker hardware, but it would be a relaively simple port.

PS4 ---> Wii U would take considerably more resources. A completely different architecture (3 core CPU vs 8 core CPU, one being PowerPC and the other x86) would mean a lot more optomization would have to be done on the code to make it work. The Wii U is also much weaker than either the PS4 or Xbox One, so that's further optomization that needs to be done to get the game running smoothly. With the Wii U having such a low third-party attatch rate, many devs are understandably not going to pay for the porting process when the profits may be little to nonexistent.