It's also a Survival Hunter, Shadow Priest, and Retribution Paladin talent.
You are correct, but like my guild, most don't have available 20x of every class and spec, it's rare when we have a replenishment in anything now. That alone will force most locks I know to go destro, however I never will as I hate the spec.
Ergo, no raiding for my lock. Sure I can suckle the nipple of Blizz's temporary class changes, or play what I enjoy.