As a DPS main myself, I resent the expectation that I should just shut up and carry underperforming DPS through content. Team content means that everyone should be pulling their own weight, not that one or two DPS should be doing 80% of the work.

And yes, if someone is in low-level gear but doing appropriate DPS for their gear, they are pulling their weight. Someone in i120 who is doing 200 DPS is very clearly not. Sure, you'll probably get through the dungeon just fine-- thanks to the other DPS, which is hardly fair to them.