I guess it's better than rifling through the laundry pile for a musk mask aka spidermanning.
That's the thing - the smell (or any discharge as such) has never been a factor - in fact, I prefer freshly laundered if anything. Whereas the smell of actual women's fluids and such is a turn-on in real life.
Which makes me thing it's just some hardwired teenage thing that's only slightly less embarrassing than Spidermanning, which at least makes it into popular culture in a slightly-favourable light.