Why is it that the truly disgusting questions don't require a warning?

Why is it that any question that mentions sex, no matter how innocuous, requires NSFW, but the questions that really require a warning (like this one), can be published without warning? I nearly puked upon reading that question. It was so disgusting I can’t believe it is allowed.

We need to have warnings for questions like that. Those are really disgusting. Sex questions look safe for daycare compared to that one.