That’s simply not true. While the greater community might not know about the “average jerk”, those who have played with them did. And when “Jerkplayer” asked to join the group, they were told not to invite that jerk.
Now, it’s true, “Jerkplayer” could probably find groups eventually, but it would get increasingly difficult until they either changed or a lot of people on the server did in fact know and would more or less blacklist that player.