Yes. For example, I'd rather catch a male Scraggy than a female because a male Scraggy makes more sense since Scraggy is a masculine Pokémon, in my opinion. It really depends on the Pokémon for what I prefer, because I just look at a Pokémon, and most of them (not all of them) tend to look more of a certain gender than the other. Most of my team is males, though. I restart a game if I choose a female starter.