Oy, I just noticed a grammatical error in my post, which my phone created with autocorrect. "It's cooldown" should be "its cooldown". Dammit autocorrect, if you're going to be useless, at least be hilariously useless.
But anyway, Jugg has more cooldowns because we get very little in the way of passive defenses outside of heavy armor, while Powertechs get fantastic passive mitigation. Pyro has 30% dot resist (good against vengeance, lethality, concealment's AB, other Pyros, and madness/hybrid sorcs, which are all powerhouses), AP has 30% AoE resist, as well as automatic +30% to all when stunned. The best passive Jugg gets is 4% DR deep in the Veng tree.