Not everyone does that, though. It's only a small percentage of the player base that does.
The majority of players are willing to work together as long as discussion about problems is polite and constructive. If you run into one of the "you don't pay my sub" types that doesn't want to cooperate, the group has the right to remove that player from the group.
So remove them, get a replacement and let the group continue progressing. So much can be so easily resolved when people are willing to communicate and listen instead of slamming up a wall.