I don't really know, maybe bigger teams only? Really I can't think of amy other game that suffers of this problem. And Join In Progress isn't really that bad in other games either
Halo is the only game on consoles with skill based MP... JiP doesn't work with a skilled based MM system, unless you ask people to forfeit their stats everytime someone quits... Which isn't something Halo fans would agree with AND it would hinder the ability to accurately guage people's skill levels