1) Warriors are a hybrid class, not a pure.
2) Rogues have like what, 3k hps?
3) Warlocks spend 10% of their hp for a fear every 10sec, and 15% hp to restore 20% mana. They get extra healing cooldowns to compensate for that
Also, we ain't given bigger cooldowns, hybrid tax is gone for years mate, a hybrid is the same as a pure in terms of damage, heck most hybrids actually do a lot better than most pures, not counting mage.