Very true. Has been the case since season 5, too.
had 1% representation through all of TBC, the "glory days" for most PVPers, and suddenly shot up to 8-10% in S5 (back down to half that after nerfs). In many eyes they came out of nowhere. Plus they're a unique class, ranged physical damage, and they don't fit in the "box" of caster/melee/healer. Very few people were used to dealing with them, and thus didn't know how to counter them. That breeds hate and "imba" cries, because you don't know that you were doing something wrong when you lost.
Not exactly the case now, but old biases die hard.