Tanks that pull 3 packs at once when any of the following are true:
1) They are undergeared
2) Their DPS are both MNK
3) Their healer is undergeared
After the expected wipe, they bitch about how long the dungeon takes when you go one group at a time.

This one always kills me because it is SO easy to spot when pulling multple packs is a bad idea. If your healer has under 3.5k health.... not smart