I feel like a lot of warlocks got a big head early on since everyone was like "WARLOCK OR GTFO" during VoG, back when people just wanted to push bosses off of cliffs. Now they've been pretty marginalized. There's a few instances where they're immensely helpful (like sunsingers making a shitload of orbs in CE Hard Mode, and self-revive to save a Nightfall) but for the most part, Hunters and Titans are where it's at especially in PoE. Maybe it's punishment for making all those Atheons and Templars commit suicide.