Most do not use their skills properlly and at the right time. Examples:
Group has to move fast to a safe area to avoid ass pulling, hunter ass pulls and was way behind.... didnt use aspect and ran mobs to group rather than FD. Wipe.
Fighting mobs in a 5 man, tab targets a group 2 pulls ahead and auto shoots it. Wipe.
Group speed running DM or group runs back after wipe, doesnt use aspect, or i didnt train that one...
Tank pulls group, hunter multi shots every freakn time before aoe aggro is established, watchs adds come to him and runs away from group rather than FD. MANAGE YOUR THREAT!!!
Warrior is alive, pet taunt is on, half way through group you finally turn it off after being told 10 times. Tank dies or healer gets aggro on an add, never uses pet to tank.
Rolls SP gear from warlock mage for serp sting, arcane shot.
Jumps from ledges and take 5man shortcuts with pet not dismissed. Wipe.
Never uses fire traps on aoe pulls.
Sees healer or another dps trying to kite/get away from a mob, they never concus shot or wing clip to peele.
I can go on and on. All the tools in the world, and you can only multi shot on pull or start with aimshot.