I personally have problems with hunters in arenas, when clearly they are not good.
However some things severely affect gameplay without having a huge effect on class viability. Usually when someone jumps my charge I can still hamstring them before they get out of range... doesn't make it any less frustrating that a 1.5 second stun and gap closer doesn't even let me "close the gap" sometimes.
Or, say, rogues. Warriors have absolutely nothing, bar heroic leap which will get you killed, that we can use with a greater range than sap. I can know where a rogue is, even thunderclap him out of stealth... but he'll still get the opener. This barely effects the outcome of a match, and there really is alot of bullshit to pull you out of stealth from a rogue point of view, but it's maddening as hell that
I guess my point is that not everyone asking for buffs thinks their class is underpowered, there are just alot of broken mechanics that I feel like I could fix if I had the resources blizzard has.