I'm still in the opinion that if you choose to use DF, you SHOULD be expecting new and inexperienced players joining you. And you SHOULD be accommodating, for the sole reason that they most likely have lesser alternatives than you, someone whose been playing for a good while.

In the same breath, I think Party finder should be more encouraged. When people go through the MSQ and they encounter a dungeon in order to progress, the message usually states to use DF. So honestly, the DF party would be more like a 'learning party' than anything (and in my experience, progressing through MSQ, I honestly had little to no idea PF as an alternative), and to expect otherwise is pretty selfish.