In reply to Offwidth:
> If you look at climbs with established HVS labels the easiest ones are arguably 4 grades below the real tough ones like Masochism.
But if your argument is valid then it needs to be valid without resorting to pointing at clearly mis-graded sandbags of the "way too hard to be E1" variety.
As I see it, the grades S, VS and HVS are indeed pretty wide (compared to French grades). HVS, for example, going from Knight's Move at the VS/HVS border to Suicide Wall (Cratcliffe) or Delstree (namely, actual HVSs, not sandbags).
Of course the commonest leading limit is around S to VS, so many people will be most sensitive to graduations around there, so many might want the finer distinction of a sub-grade.
But, if you did promote HS to a full grade in its own right then it would be a very narrow grade, far narrower than, say, HVS, which makes less sense.