Trolling before games. Why can't there be a vote to dodge?

I want to understand why bans, reports, and attempts to call out trolling have to be postponed till the end of matches. For example, I am in a lobby for ranked, in my promos, I am in mid lane so I click Zed to declare. A team mate bans him, I think "why" but then declare Yasuo. He is directly banned by the other team mate in bans. Yet, I have to sit through an entire game and most likely get trolled (me assuming based on the current situation) just to get a chance to call out and persecute two trolling players. Why isn't there a earlier plead or means of outcry in these types of situations if I need to dodge for the sake of the other 2 players, along with myself without receiving annoying penalties? Mind you that my opinion may get overlooked because of my low rank, but my point of view should not be discounted any less because I know first hand others that face the same problem. Especially when I'm in promos and it counts as a loss. Why not put in a three vote system to exit back to queue? Or maybe a report for intentionally trolling before games too.