Once someone leaves you can leave yourself and not get a penalty so I dont see the probelm. Like ok yeah it's bad, unfair we dont get another player to join in but honestly if the match is already loosing with 5 deaths and crystal just in 2nd checkpoint, it's all ready a lost match. I can see why people would leave. On the other hand, if the match just started and somone leaves, the game should allow a player to queue in during match in that 30sec starting window