That is sort of the question here....
Why? Why does it matter?
Morals are largely an emotional thing, you can't always help the way you feel about something. The brain and the mind perceive things a certain way. And is it really that hard to see why someone wouldn't want to be with someone who's fucked enough people to fill a building? It shouldn't be difficult to see why someone might have qualms about sexually interacting with someone who's already been touched by an endless number of people before you.