Yeah yeah, we all know it's not balanced around 1v1, 2v2, 10v1, 9v343 etc, blah blah "get a dispeller" the usual herp derp and stuff, but lets face it - even though it gets dispelled instantly in arena or when you have a pocket dispeller on you (making it kinda "balanced") - it's HUGE when you don't have a dispeller on you.
Basically it totaly locks out a rogue or forces him into using a long and valuable cd against something that can be reapplied with ease. Stealth is our key ability, we are useless without it. Ironically enough, for some reason we can't even vanish (which is also our key ability that shouldn't be used against a spammable spell) out of it like we can out of hunter's mark.
I mean, imagine a single spammable spell that would lock a druid in his current from without letting him shapeshift without using, for example, survival instincts? Even if it can be dispelled by a healer - would it be fair? I don't think so. Yeah it would probably be ok in arena with a dispeller on your arse but would such a spell be justified? I Doubt it.