Last night, a Frost DK (not in full PvE gear) crit me for 10,125 Frost strike, after chaining me 10 yards away then walking up 3 seconds later, while I was evasioned. Poof. 10,125. No setup required, no precasting, no stacking debuffs.
Consider that your versatility; 10k + damage on a full furious target who has defensive cooldowns in place. Compare that to Ret paladins, Destro locks, rogues, whatever. All of them require either a : more buttons, or b : more setup.