What exactly about VH was metal? I never thought of them as metal.
As far as guitar tone aggressiveness, I figure if VH is "metal", then so is KISS. But we know that ain't right. Hard rock? Sure. Metal? Not even.
Neither VH nor KISS had an aggressive guitar tone... more vintage cranked Marshall *without* scooping the mids.
Hair Metal = Dokken, RATT, Motley Crue, Whitesnake (once they did eponymous album with "Still of the Night"), Europe, Stryper, L.A. Guns, Skid Row, etc...
Seems glam plays a role in the "hair" part of "hair metal". I think it's safe to assume that "hair metal" = "glam metal".
So perhaps scooped mids aggressive guitar tone + teased hair = "hair metal". That sounds about right.