Then don't join harder endgame content if you aren't willing to contribute at a decent level. Why does their fun trump everyone else's? Those other players aren't there to entertain you but to clear the content reasonably efficiently. If you can't perform decently, you're making it less fun for them. Which is selfish.

To put another way. If your goal is to simply have fun and not worry about your damage. Go find a group or FC of like-minded people. If it comes to a point you can't clear because no one is putting in a serious effort, maybe you'll discover why that mentality isn't appreciated by others.
Ofc, I agree 100% with that. I'm not defending in any way any player that expects to be carried, that's unpolite and rude.