You can easily switch the 'party finder' argument around. If you want to play to below what your class is able to do (since the meta is that heal dps) then you should find like minded people. Otherwise when you meet strangers then you should be putting in the effort, or expect a kick. Seems the duty finder is used by some because they know they're unlikely to meet people again, so they don't try.

My understanding is this is how the Japanese servers do it. Party Finder = Practice/Play to below standards (often as practice) with others like-minded. Duty Finder = Full effort as playing with strangers (don't want to be rude).

If you're playing with 3/7/23 other strangers who find your poor performance to be a hindrance to them, then don't be shocked if you get kicked. You're playing with strangers as a group and should be making an effort beyond hitting 3-5 buttons and spamming the jump bar. If everyone in the party did that then the dungeons would take forever and, since the game only has two dungeons in the expert, would likely result in a massive fall in people doing them. Killing the game at the end, all because people couldn't be bothered to try because " my sub, screw trying as a group with people I don't know"