I hate crucible, so it doesn't matter to me. But, just a thought, why not institute a ladder? Increase your ranking to climb the ladder. Maybe have some crucible activities be independent of the ladder while others force you to play against others on your 'rung'. Some tryhards would throw matches to be able to keep their ladder ranking low but most sweats wouldn't be able to help themselves, they'd climb the ladder. Scrubs would play on the lowest 'rung' until they got better and improved. I don't see a downside, unless there really aren't enough people playing crucible to fill out the ranks.