You forget that Wii U also had 4x more RAM.
At end Wii U has much better stronger GPU with twice amount of RAM than PS3/Xbox 360 but somehow slower CPU and RAM, so Wii U have similar power like PS3/Xbox 360 and even slightly above.
Lol what good is having even 1000x more RAM if you can't ever use it. As a developer you would be more concerned with the speed than anything else. What good is having a 16 lane freeway when the speedlimit is only 35mph. I'd rather have a 4 lane highway running @ 70 mph so you can get all those cars home faster.
Lets review the Wii U's system specs vs PS3/Xbox 360:
- 50% slower RAM (12.8gbps vs 25.6gbps for PS3)
- While Wii U has 2GB of RAM Nintendo reserves a full 1GB of that for System resources. That 50% wow. (PS3 was always lamented by developers for reserving 19% of RAM). So in reality developers only have ~2.4x more RAM not 4x as you claim and its slower.
- 50% slower CPU. This is being really generous here. The Wii U is 32-bit. Has a clockrate of 1.24ghz. And is based on the IBM PowerPC 750 (1997). 32-bit architectures started going out in the late 90's/very early 2000's. Even comparing the clock speeds is bad (1.24 vs 3.6) because the Wii U can't do as much per CPU cycle due to being only 32-bit. GIgaflops paints even worse picture: (3.72 gigaflops Wii U vs 10.8 gigaflops Xbox 360 vs 23.04 gigaflops PS3).
- GPU is next...
- The PS3 gpu has a performance of 228.8 gigaflops.
- The Xbox 360 gpu has a performance of 240 gigaflops
- The Wii U gpu has a performance of 352 gigaflops
- Meaning the Wii U GPU is between 32% and 35% more powerful not 50%