I once joined a shisui dungeon in progress and the healer was apparently refusing to heal because the other two people vote kicked their dps friend for being afk. Apparently what had happened was the healer had to go away for a while and their friend took over playing for their character to heal and I guess the other two people didn't realize and just saw the DPS being afk and kicked that DPS. So now the healer doesn't want to play with them and did not want to take the penalty for leaving while the other two are refusing to vote kick the healer out of spite and I was caught in the middle of it. Needless to say, we nearly didn't complete the dungeon, but thankfully it was near the end by that point, so we somehow made it through.

When it comes to an MMO where you play with other people, I think those people can be considered "bad players" in that respect.