There's no much use crying over the AI. We're in Gen VI, nearly 15 years after the first game released, and they never made any effort in increasing the AI. It's not like they can't, it's that they don't want and won't. In the end, the target audience will for Pokémon games will always be children, and they have to make the game accessible.
Of course, there's always the possibility of adding difficulties, but aside from the Challenge mode in Black (which doesn't really get an AI boost either), they never did it before and dropped it this Gen. I think there's also the intention of Game Freak in making the game easy, because aside from children, the other target audience are more casual gamers. Game Freak doesn't want Pokémon to be a difficult strategy RPG, it wants the game to be simple, easy and fun.