One of the reasons I hate it is because it works better than my beloved fury spec for what I do in raids, which is dealing damage. It's gotten to the point where I'm usually dual-specced arms/fury, arms for most bosses and fury for trash clears. I haven't specced arms because I like the spec... I find the reliance on procs irritating, always waiting for Sudden Death or Taste for Blood, never knowing when they're going to proc, having a timer on my rend up time so that I never let it fall off but don't waste rage... it's effective, and I know there are lots of warriors that like it. But I don't. Although I do love using Bladestorm while defending a cap in Alterac Valley, I'll admit that. Those poor hordies trying to take Tower Point back did not expect that.
So maybe I don't hate arms spec. But it's not my spec of choice.
The reason I've dual specced arms is because of the recent nerfs to fury. It's not a secret or a surprise, arms just does more damage than fury right now. I'm sure I'm not the only player who's ever used a spec he or she didn't like simply because it performed better in their chosen role playing the game. For that matter, I know lots of players who play a spec and role they hate just because that's the spec/role their guild needed or asked them for. So now I ask you: have you ever had to play with a spec you hated?