Option to vote out.
I believe that the game should not load if 1 or more people have not connected yet, and there should be a waiting period during loading to give that person a chance to reconnect. If the period expires and the person does not connect still, you should give the 4 people a warning message saying "Your 5th person has yet to connect, would you like to exit this game or proceed with 4?" Or something to that extent. Instead of leaving the 4 people to pray to god that they don't have a 5th. I queued up yesterday and after exhausting every single trick I knew how to do, the game continued to refuse my connection and I had my first true AFK game. There's been games where it took me 5~10 minutes just to get in awhile ago, but this is the first time I've had the game completely refuse to let me in. I genuinely hate when people AFK, but it's frustrating when there's nothing I can do about it, because I hate screwing my teammates over.