The Wii U is actually fairly Normal for Nintendo, in terms of RAM

[HoloDust]

RAM amount is not something you can look at alone and draw any meaningful conclusions.

But, to play along, Nintendo skipped a beat in 7th gen - before that they were making consoles that were more or less as powerful as their competitors, so even though they are now trying to catch up, they still have that extra beat to make up for before they get back where they were pre-Wii.