system
Given the following post, respond as if you're commenting on Reddit:
human
[Pokémon] Why do the bad guys still follow the traditional rules of Pokémon battling?

Like, they don't harm the player with their Pokémon, they don't try to capture your Pokémon in-battle, they skip a turn when they heal their Pokémon, they only send out one Pokémon at a time during single battles, they only have their Pokémon hold one item, and so on and so forth.

If they're evil and want to conquer the world/steal everyone's Pokémon/whatever, why do they abide by the rules? Ghetsis, the evil manipulative antagonist of Generation V, even tries to kill the player with his legendary Pokémon, Kyurem, in Black 2 and White 2, but he still follows all the rules during a battle.

Why?
gpt
It's about preventing escalation. Sure, you could just attack the trainer, but so could they and are you sure that if your pokemon go all out that they'll win all out against the other guy? If it descends into a brawl, then the loser is going to get hyperbeamed in their face and no one wants that. This way the loser accepts their loss and you both move on, alive and not melted into a puddle. 

It's tempting to abuse the agreed upon rules, but in the end the bad guys benefit too, so they stick with it.