RE: I always hear this story...
GMMAT just because a mature deer does not "work" a scrape does no mean he did not check it.
Most of the time IMO mature deer check them from down wind side where they can not be seen. Why I seldom sit "over" a scrape, but in funnel he may use to scent check it from a distance. I will be downind from the scrape, and be setup so the deer is in front of me.