Quitter penalty is basically a necessity because of SBMM. The main complaint that spurred the change is people were upset they were getting stomped in some games by people pointlessly k/d farming in a casual playlist(I don’t know why this is a thing). So some players were upset because they are to obsessed with winning even though winning and loosing don’t matter, it’s a casual playlist. When Bungie decided those were valid concerns and changed to SBMM for a casual playlist they declaimed that concerns about winning were valid, even though it’s casual. So with SBMM the teams are balanced based on player skill so when you leave that balance is ruined and those playing no longer have an even shot at winning in theory which violates what Bungie put SBMM in for. So the penalty is needed to prevent the petulant childish players who are quitting and harming that win chance that Bungie has deemed important. The system can’t care why you’re stepping away. Anyone stepping away from a game harms the precious chance of your team winning which is all the players Bungie made the changes for care about.