98% of rogues dont know how to combo or use stealth properly. (or backstab the sheep, etc)
98% of priests dont understand the 5 second rule or will consistently overheal, and fail to use flash heal in emergencies.
98% of shadow priest refuse to heal, EVER. >:-/
98% of warriors cant hold aggro/dont get aggro on Adds/aggro when DPSing
98% of mages like to pull mobs off even the best tank just before they go OOM
98% of warlocks scare the shit out of their healer by lifetapping to 1hp mid-combat.
98% of feral druids dont switch out of cat/bear to heal themselves even if the healer has announced theyre OOM.
98% of balance druids... cant think of much. fucking OOMkins/Noobkins. Healing problem from feral applies here too.
98% of resto druids.... dont exist. yeah, like anyone levels a druid on resto. Of course, at 70 they're noobs all over again.
98% of hunters cant control their pet, or at the very least, dont bother healing it in instances.
98% of shamans dont understand that they can heal, Melee or ranged DPS (or even all at once) and tend to pick only their favorite totems in group situations, even if another shaman has allready dropped the same buff one. Or they dont use any. or they drop them before pulling, then leave them behind as the warrior rushes in instead of pulling.
In conclusion, 98% of all players dont understand pulling, tanking, aggro managment or even plain english, and therefore suck.
further conclusion:
98% of all people online dont understand or speak plain english (or their own native language) and therefore suck.
final conclusion:
Theres a 98% chance that you, YES YOU, suck.
Listening to machinae may decrease your chances.