I'm sorry but those tweets...
"from what I hear if powerpc used right can look as good as Xbox one."
"Lazy devs..."
"I don't expect it to be as good looking but I just know you could have done a better job."
"Because of the delay I'm gonna "get" it on PC anyways, otherwise Wii U."
There's no basis at all for demanding X1 like performance out of Wii U. These people are just going to piss off devs with their blind whining. If Wii U was clearly superior on all levels to 360 then you would have an easy argument, but the Wii U's CPU is underpowered.
Wii U can issue 3 instructions @ 1.25GHz and 360 can issue 2 instructions @ 3.2GHz. i.e. maximum theoretical on Wii U is lower (3.75Giga instructions vs 6.4Giga instructions).
Of course, the Wii U's Out-Of-Order engine makes it much easier to get close to that theoretical maximum than the X360 without lots of optimization, and this is where the "if they used PPC right..." argument doesn't make sense. Both Wii U & 360 use PPC architecture, but the Wii U is more advanced with OOO. There is less that a developer can do to make an Out-Of-Order CPU run faster than an In-Order CPU.
Another way to phrase it is that any PPC optimization, is going to make a bigger difference for X360 than for Wii U. Therefore, it's not more PPC optimization that will make Wii U games better than X360!
