Rant: Off-role trolls.
Came off a game where our mid laner was a support main and our support got autofilled mid. Our support asked if they could mid and our mid lane bans his hovered pick and went mid. Everything should be fine right? Nope. So after I picked an off-meta jg, our mid lane then decides to troll by switching to raka mid. Not because they're playing off meta, they explicitly said "I got a better troll pick". Despite me doing well for most of the game, 3/3 dragons, rift, not feeding up until mid game, they blame me instead of the 0-8 yorick and 0-8 brand because those champs are "meta-picks". And guess what, in the end they don't lose much from the loss because it wasn't their main role.
I think the role system is a decent idea as long as it is implemented correctly. The current system allows too much leeway for trolls to int games without hurting their real mmr. I say put all off-role people in one queue and all main role people in the others. This way even if troll exists for off-roles the other people on the team won't lose much either since they're playing their off roles as well.