True enough, but my point is simply that I wouldn't find it to be a good addition becasue of personal reasons. Another thing is that to me, although Pokemon are childish, the're also:
a) Unique; all of them are interesting creations that you would never really see anywhere else, with amusing expressions or movements. When it comes down to it, Diddy is a monkey.
b) A big part of Nintendo; Countless Pokemon games vs. a couple of games that feature a better character's sidekick . Although DK is also a monkey, I find he fits better because he has a greater legacy, and is a main character/Nintendo icon (moreso than Diddy, factually).
c) Better and more impressive fighters; We're seeing electrical strikes, fire-breathing, claws, psionic blasts, beams of energy, or anything really. Again, Diddy is a monkey.
I'm sorry, but I just see way more feasability in other characters. One giant monkey in the game is enough to me.