How about not allowing players on ranked loss streaks to continue queuing for ranked?
If nothing is going to be done to punish individual poor performance, this really needs to happen.
Teams should not lose LP because a player who can very clearly be detected as tilted just queued up again after his 8th consecutive loss. Force them to win a normal before they can continue with ranked.
This bullshit of allowing players like this to continue queuing completely sabotages the entire system.