I always think it's harsh to have 'hate' clubs, as you can't hate someone you don't know. Hate is such a strong word as well. Furthermore, I don't know how Zac Efron can invoke such emotions, but then I'm biased.
I suppose it's possible to dislike him because of what he does or the way he puts himself across, although that's part of him and I don't think he's done anything to make himself viewed as smug or snake-like.
But hey, each to their own when it comes to opinions, as always.