We have yet to see others of its species in the anime, so it could just be this one that's so messed up. Maybe the others are lonely and don't have a hatred of Pikachu, just the desire to be popular like it. Team Rocket's Mimikyu seems like it has a profound hatred of Mimikyu, and it seems more selfish than most of Team Rocket's Pokémon as it never displays any affection whatsoever and actively frightens them. You'd almost forget it was a Fairy-type.
