Like... it seems like they were primarily thinking in the sense of "Arms is the only Warrior spec." Honestly, it seems like a common theme throughout the new talent system, but Warrior's the class I know best, and as a Protection Warrior, I feel like we got pretty screwed compared to Arms and Fury.
The reason being, a lot of what made Protection interesting and/or useful in PvP (the utility the spec provided) was turned into talents and/or glyphs. Not only does this mean Protection's pigeonholed into specific talent choices in order to have the same utility they had before, it also means that these talents and/or glyphs are going to get nerfed based on them being used by other (read: Arms) specs.
Shockwave? Turned into a talent, and now it's going to be nerfed in 5.2 because Arms is overpowered with it in its current iteration. No real change from PvE (since you're always gonna be blasting packs of monsters with it, it'll always have the basic 20 sec cd), but it's a pretty severe nerf to Protection, despite Protection not overperforming as far as I'm aware.
Gag Order? Turned into a glyph, and now made unusable in PvP because Arms was overpowered with it. Again, still usable (and useful as hell) in PvE, but it's another major hit to Protection in PvP.
Concussion Blow? Straight up removed. Storm Bolt might be able to be seen as a sort of replacement, though; but taking it means either no Bloodbath or no Avatar.
Safeguard? Turned into a talent, also nerfed slightly.
Hold the Line? Now it's a glyph. Shield Slam dispel? Yup, need a glyph for that, too. Heavy Repercussions? Glyph.
All of this would be fine, but we still have glyphs that are pretty much mandatory for PvP - the extra 5 yards on Charge, the 15 second cooldown reduction on Heroic Leap. Honestly, I'm fine with the Heroic Leap glyph since it's not required for PvE (though I'm seriously wondering why it's losing the damage boost in 5.2; how was Heroic Leap hitting for 20k instead of 10k an issue?), but why isn't Charge a 30 yd skill by default? Incidentally, this issue still exists with DKs, too - they still have to waste a glyph slot for Death Grip, too.
I dunno; maybe I'm just being bitter. But it feels like in their efforts to increase diversity among classes and players of the same spec, they've actually made some specs even more pigeonholed than they were before, because rather than inventing new ideas or skills for talents, most of them are abilities taken from Cata-era specs.
I mean, yeah, Arms no longer gets Bladestorm for free, but they still get a choice. Since Prot's only use beforehand was not dying and using their control abilities as utility, we don't really get a choice - sure, I could take Avatar and Bladestorm and whatnot, but I'd still do way less damage than Fury or Arms, while possessing none of the inherent utility or control I used to have.