I've only had one really bad experience and it was in Haukke Manor. The other Thaumaturge in our party thought he should be the leader and knew all the best tactics. All he did was complain and insult everyone in the party and constantly caused us all to die. During the first mini boss he sat on the sidelines. We just left the duty and waited our 15 minutes to enter again. I think it is unfortunately inevitable that we will all run into rude people in this game and it is probably best just to report/blacklist them. I'm all for people offering advice in dungeons but if that advice comes with a side of sass I'll pass.