Maybe this game needs a more Eve-online attitude
Over in eve-online, people are always saying that by clicking undock you consent to PvP. Most mmos are pretty carebear when it comes to PvP and griefing, but eve was one of the few that never was.
When it comes to ranked, part of me thinks that riot is never going to do some of the things we want, like dealing with AFKers, stomping toxicity completely, or giving us the ability to kick trolls in pregames (I'd even be happy with a report & dodge feature where you can report someone in pregame if you dodge).
Maybe we as LOL players need to toughen ourselves up mentally a little. Like it or not, you are going to have people trying to ruin the game for your team. Maybe we need to start saying that by clicking on ranked, we consent to playing with trolls, toxic players, and AFKers. Not because those are good things (I say report them all because it sucks getting one on the team), but because it's going to happen so you might as well accept it is going to happen if you want to play in ranked... esp in promos and then you fall back to 50lp because you know that for 2 out of your 3 losses, someone on your team is going to throw the match.