As having played Vanilla extensively, i feel that what people want is not Vanilla. Blizzard was exactly right in saying "you think you want this, but you don't". People begged and pleaded for Vanilla Servers, and now they are getting them, but that is not good enough. Now they want Vanilla, but with more. Not just this thread but others, they want dual-spec, they want class/faction equality (pallies and shamans on both), they want so many QoL changes that it would not be Vanilla, it would be Vanilla, with chocolate/strawberry swirls.
Blizzard was exactly right. You thought you wanted it, but you didn't really want what was being asked.