Basic reading skills... you're doin' it wrong.

The guy above did not say this item is good for only warlocks.  He is simply describing how good this item is, from only the warlock perspective.  Presumably because he plays a warlock.

This is an upgrade to the Destructo Holo-gogs, which is the caster dps goggles for all cloth wearers.  These goggles are great for all cloth dps (and no one said otherwise).