The sites themselves aren't the problem (generally)
Public pugs simply attract miserable people. The crowd nobody wants in their dmix servers
Some don't care. They'll feed 24/7
Some care too much. They'll whine whenever things go wrong
Combine the 2 on one team and you get a miserable experience for everyone in the mumble.
So half the team doesn't re-add after the game and pugs are dead for the day.
Eventually you stop altogether because you know who'll also add up and it's not worth it.
The proper solution is to permaban based on vibes if you want it to be public.
The practical solution is to make a private dmix server. It also dies, but you tried I guess.