When you join a party meant for farming your expected to know what to do and how to do it. Calling that person selfish for removing you from the party is a bit rude as you yourself join that party to clear it for the first time instead of farming, so you technically lied to the party.
You may want to clear this content but getting angry for people kicking you for joining farm parties isn't the way to go. I'd say find a group of people you can run with like maybe some friends or something but thats getting old now. Open the party finder ad ask for some players to help you clear the content with lvl snch off, you'll draw in some helpful players like that. I feel your annoyance though, its basically old useless content now to previous players and not many are willing or even thinking about stuff anymore, its not your fault for being to late, its the requirement of multiple players to even do this stuff. Its only for story anyway, the weapons aren't even necessary now. Good luck and happy questing dude.