Thanks for the alternative views, I realise other players have many different motivations for playing and I didn't mean to make it a LP specific discussion.
I more want to steer this towards generating ideas for alternatives or changes to the probation system. There maybe isn't a solution, but I think we can do better than the current system. There will most likely always be a way to abuse the system, most likely why they have never provided details about the scoring and ranking in LP, if they did someone would find a way to abuse it.
I personally prefer the concept of an incentive, though I don't necessarily want the punishment to go away. I also don't want it to be possible for players to join a game and do nothing and benefit, I believe players get kicked for inactivity in LP(?)
I guess in the end I hope that matchmaking on the Xbox one is able to determine between players that regularly quit and those that don't and match them up accordingly. That is probably a better solution to fight the problem at the source, rather than try to change people, just match like minded people.