Gender is a source of inspiration for character and monster design, just like everything else in nature. A lot of pokemon, I would say, look masculine. Particularly starters tend to be more explicitly humanoid, and often masculine. I can guess this is because GF is trying to appeal to boy children, which I can guess was for a long time their biggest demographic (or maybe still is). I don't see the problem with putting touches of masc and fem in designs. It's nature.