The problem is that you have two things to look at.
A) class damage and utility
B) spec damage and utility
Many classes can just say, oh, B) isn’t great for X, let’s use my other damage spec instead for this season. Typically warriors can do this because at least one of their two damage specs is performing at least “middle of the mall,” as you said.
If you have neither A nor B above what, say, the best hunter, warlock, mage, rogue, DK spec can output, you’re going to be worse off than someone playing those specs until they bring them in line. It’s virtually guaranteed that at least one spec for rogue, mage, warlock, hunter is going to be viable as they have 3 DPS specs to choose from at any given time with wide variances in performance.
For the most part the first tuning pass was very mild and wowhead is suggesting pretty bluntly on their article today that they need another 5-10% tuning on Fury. I guess it will remain to be seen where Arms ultimately places. Wowhead is saying that the Mortal Strike debuff amounts to about a 4% buff with Condemn.
There’s so many variables it’s kind of hard to do any realistic meta analysis, but player perception is the really key component. If players feel like you will underperform based on what wowhead, icyveins, whatever online source told them to think a certain way, you might get dumpster binned from higher level content and struggle a bit to progress when gear is light.
I don’t think it will take 2 tiers for at least A) to get to the point it needs to, but you’d be right to be rather annoyed if you spent 75 grand on legos for the redheaded stepchild spec. That’s kind of across the board, though. I think people who started middle of the road probably will have it better off right out the gate. Another reason why the spec-specific legendary gating system infuriates me, but so it goes.
Someone who had a spec out the gate that they could plot around, that wasn’t going to be changed throughout has had a leg up on legendary progression.