Sometimes a group just doesn't work out, we have all been there. When one member of a party is making things difficult for everyone else in the party, but once your in a group in a quest, you are safe. Your behaviour no longer matters, you can lip off, sit still, or just generally be a non contributor, and you are going to get xp if everyone else stumbles along anyway.
I feel that this is really an untenable situation that leaves many people preferring to solo instead of risking often risky player dynamics of an unknown group.
Here is my suggestion;
The leader of the group should be able to boot a player with the support of half of the party in play.
For example, you are starting a quest and once inside, one party member says that they are not going to aide the party, and they will just sit at entrance, party leader could elect to boot member, whereapon a pop up window would appear saying, leader "xyz" has asked to boot player "abc" vote yes or no. Three votes and player "abc" finds themselves outside the quest not in a party.
To be fair, on a failed vote call, the leader would be the one finding themselves outside the quest.
What say you all?