I can't think of a single figure, for whom this debate is applicable, who truly matters in a historical sense. Not King Arthur, not Johnny Appleseed, and sure as heck not no dang Robin Hood.
Should we teach the facts behind the legends? Sure, to those who care. But do the facts ever supersede the legend in importance? Nope.
There's a reason the legends have become bigger than the men who inspired them, IMO.