Because this matchmaking is hot garbage and I'm tired of getting these wacked out teams where one side is loaded with burst and the other side is a bunch of support classes that can't kill anything. Like what is my team of a brd, blm, pld, sge, ast supposed to do against a whm, sge, drg, sam, nin?????

If square wants this mode to work with no role enforcement then the concept of support/tank designs need to disappear.