Duty finder is never going to be the answer for people looking to play with mature players or people not ditching halfway.
The entire concept of it breed toxicity like people have been encountering, 0 accountabillity and a massive likelyhood that you will never see a single person you play with again makes being a moron very easy and have no blowback. Play with people on your server if you want a real experience, get a free company with lots of people or hell start your own and start inviting new/old players alike breed a community.
Don't expect the duty finder to do it for you, we had to work hard in FFXI to make our community what it was. The game had hardships and with them the community grew to overcome them, in a game with a lack of real challenge until the endgame weaning people on a system that fosters not needing to really communicate and then suddenly saying.
"OK IT GETS REAL HERE!"
Is no way to design your game...but eh.
