I'm competitive. I simply won't play FPS that have aim assist in multiplayer. If a controller has a disadvantage to KBM, they should learn to use KBM, not give them a built-in aimbot.
I don't think I could bear to spend ~ 10h / day at a computer, and then spend my down time hunched over a keyboard and mouse. I like a clean break, and a completely different experience.
You're welcome to be as 'competitive' as you like, but the rest of us want to come home, sink into their favorite recliner and casually enjoy a game for a an hour or two. It's a game. Games should be fun. I swear people act like their K/d ratio buys groceries.
Aim assist is a big change to a game to me because it necessarily introduces an opinion about how much assistance controller users deserve into the equation.
I get that controllers are not as precise of an input mechanism as mice, but how much worse? How much does having aim assist allow you to play a style that PC players can't? E.g. some implementations of aim assist make quick scoping very strong.
It also just feels really crappy to watch a kill cam and know that if you had done the same thing, you would have missed because no aim assist. The reasons why make sense, it's not a logical thing, but it does feel bad. I would imagine dying to KBM flicks feels equally bad for controller players.
I do think aim assist should exist for controllers, I just don't think it should co-exist with KBM in the same matches in competitive modes. Console players don't seem to like having KBM players in their matches either, so that seems like a win-win.
KBM is a huge boost.
His enjoyment is for him as important as yours for you. He is in fact entitled to play only games he likes to play is setup he finds fair.
And he is fully entitled to express it out loud so that similarly minded people can bond or argue for existence of games they like.
Can you see how Microsoft, maker of the xbox, might not share your opinion?