If players aren't forced to bring a support, they won't. Why would they bring 50%-75% of a dps/healer when they could just bring a pure dps/healer? We've seen, first hand. on the goddamn front page right now, players dropping extra roles in a fight to clear it faster with a "burn it" mentality.

http://forum.square-enix.com/ffxiv/t...-single-healer

How many times do we have to bring events like this to peoples attention that players will drop non-dps roles to kill boss faster.