DPS is the job of DPS.

[Reynhart]

I respectfully disagree with your idea of expectation, as I'd suggest to be open to either scenario upon queueing up. Sure, you can convince them to do otherwise, but in the end, that rule doesn't exist.

Sure, we can discuss to find a consensus, but, if that consensus can't be found because people are too stubborn, you have to backup to an objective rule. The PF was specifically created to allow people to put additionnal requirements when recruiting, allowing explicit rules that every party member accepted when they joined. There are no such things for joining in the DF except language and minimum ilvl, so, people have no right to enforce them.