Haven't really tested Prot warrior yet in the beta, only Fury(which i prefer over WoD), what's so bad about Prot?
Uninteresting talents.
Rage generation is fucked (last stand/HP talents means you're generating less rage because rage is calculated on a health percentage basis)
Loss of abilities & higher CD on revenge/SS means we're spamming Devastate a lot.
Focused Rage (our heroic strike replacement?) is dogshit.
Artifact abiliity is frustrating to use.
There's no sense of choice anymore. On live, picking between Shield Block & Shield Barrier is something that is quite important to do. On beta, shield block is so cheap the choice isn't there, and throwing everything at ignore pain is seldom the wrong choice.
So yeah, less abilities, less choice, lower skill ceiling, boring talents, a shit artifact, and WotLK style rage regeneration where people are seriously suggesting taking off armor pieces to get more IPs off to take less damage... Like, what?
In every way, it's a step back from WoD, which itself is hardly amazing.
I'm going to make a prediction here:
Almost every single spec in the game is going to be headlining "Yeah but we suck" for the first month of legion.
Too much has changed for this to be a comfortable transition.
Blood DK is actually improved, and I've heard nothing but good things about Guardian Druids.
Going from Devastate/Shield Slam/Revenge/Execute/Heroic strike as our damaging single target abilities to Devastate/Shield Slam/Revenge is dull enough as it is, but add to that the longer CDs, and I'm just fucking bored hitting devastate to no effect.
Going from choice between Block/Barrier to just mashing IP because SS is so cheap is also a step backwards.
Losing our utility spells like Vigilance (not even a talent anymore) and Intimidating Shout also sticks out like a sore thumb. I'm nothing but a meat shield with no interesting gameplay tricks up my sleeve.
It's not about sucking. From what I've played, Warriors are actually pretty strong. It's just that the gameplay is so terrible in comparison to Warlords that I'm concerned they'll be able to turn it around in a few months. This isn't an isolated opinion, either.
Paladins are seemingly in a similar boat.