That is a logical error, as a Pokemon cannot not look like a Pokemon, since a Pokemon is a Pokemon and to say a Pokemon doesn't look like a Pokemon is akin to saying water doesn't feel like water or grass doesn't look like grass.
Ignoring this, it still should be mentioned that a Pokemon is defined by Ken Sugimori, and he could say that a Cthulhu lookalike is a Pokemon and no one could argue him.
Ignoring that too, I agree that design complexity has changed between generations, but not because the design standards change, but because complexity limits change. Gen I gave us more simplistic Pokemon because the games couldn't handle complex ones. Nowadays we have higher quality sprites and we're even now moving into models. Game Freak can do whatever they want now in regards to complexity, and they're exercising that right to the fullest. I for one see no problem with something like that.