I've had enough of people banning your champs in champion select. Why is it even allowed?

Over the course of my last year of playing this game, I've had people constantly banning Yasuo even when I hadn't done anything wrong. I'M FREAKING HONOR 5, I almost never flame, and I play my own goddamn game. I submitted a ticket to riot player report and all they had to say was o sorry we can't do anything about the dodges you've made for your team against a troll or whatnot. I even saw it happen to another player and all I could do was watch him suffer, these players don't even apologize in any situation (unless they've truly made a mistake). Why do we not have a kick system so that players can vote to kick the troll in champion select. This would lower the chances of trolls affecting games by a large amount. Look I don't mind if you think Yasuo is broken or OP, but if you think banning your own teammate out is going to win you the game then clearly you're not mature enough to play the game. There needs to be something done, or at least riot needs to listen to pleads with hard evidence. Thanks, Botlinebling