If Pokémon are real, they'd be hurt by what you said. There is absolutely nothing that dictates which Pokémon someone should like. Looks are definitely not a standard.
You may not be aware, competitive battling is actually a thing. Thousands of people are willing to use strong Pokémon in order to win because not most cute Pokémon are strong. You're playing over Wi-Fi, you should just accept the fact that you're not going to change what Pokémon each player uses. If it irks you so much then just battle in-game, you'd have less reasons to rage.