Just gonna piggyback off this post a bit cause it brings up a good point I'd like to expand on a bit; I wanna point out that when people refer to terrible dps, it's not usually someone who hasn't scoured for the latest and greatest meta info. If you're pulling like 700-900dps then most people are gonna be chill with you. You won't impress anyone, but you won't piss anyone off either. We're usually talking about the mute bards, the 350dps drg, the ice mages, etc. Idk everyone else's experiences with df, but mine are pretty much this: http://i.imgur.com/fAUOr2c.png all the time and it gets annoying.
If you're a good player and you use df, then yeah you have a responsibility to do the best you can with whatever group gets formed. But why does that only ever seem to apply to the good players? Bad players get a pass every time. Bad players have the same social responsibility to at least attempt to not be awful, to not actively be a detriment to their group.