I'm a long time Pinsir fan, and have wanted a Bug/Ground evo ever since Heracross showed up in GenII. Although I like a good number of the new Pokemon, I generally dislike the direction the design is taking. The problem I have that you don't seem to understand is that I connect a Pokemon's evolutions with it's older forms, because they're really the same creature. Thus, if Pinsir does get a hideously ugly, poorly-designed evolution, my image of Pinsir would be ruined - "Pinsir evolves into that!?" Lickitung is the closest example of this I can think of right now.
I guess it's a combination of really high expectations coupled with connecting the past forms with their evolutions. Hopefully you understand a little bit of what I'm getting at!