The problem is that the meta chosen to deal with the qf is running a heavy. Heavy, although works wonders in defending against the qf, is slow and therefore it's harder to push out as a team. The counter to heavy is a sniper, therefore that's two players which are slowed down due to the qf. It's a fun medigun to use, and I think if the meta had developed differently it would still be in ESEA.
Just my two cents.