I should start by saying that I've never liked nerfs. (Unless it fixes broken bosses).
However, when I complained in the past, nerfs never actually affected me because I didn't raid Heroic. Now, SoO is my first Heroic tier, and I personally see it as a real goal of mine to beat Garrosh, after having tried really hard to work my way from normals at the start of MoP, to being an officer in Heroic guild. I play this game for challenge.These bosses are not impossible. My guild has almost gotten Thok down, in fact I'm almost certain he'll be going down on sunday. If he doesn't, for whatever reason, I'd rather never kill him than kill him with the help of a nerf. (We're 10 man, and got him really low, with 3 melee so it's obviously possible). I've partly helped build a guild and a raid team and now when we kill Garrosh I must, through no choice of my own, say 'Yeah we killed Garrosh, but only after the nerfs.' Could we have done it without the nerfs? Yes. This is a slap in the face.
Edit: we're only got 5 core players. This has little to do with skill and more to do with it being a new guild. Yet we've made it to 10, and probably 11, but will be forced to kill 12 with nerfs.
Edit: How about no nerfs at all? Let people get better/let people get gear (the natural nerf). Nerfs are NOT needed. If you're not good enough to get to garrosh before WoD, then that's fine. But there's plenty of time till WoD. So why nerf?