If given a choice between sluts and needlessly vicious assholes, I'll choose sluts every time.
Not even going to attempt to explain the fallacy of your logic beyond that, but it fails on every front. I'm not even a fan of this kind of photography per se, but I don't understand at what point people started thinking that it was ok to be as bluntly asshole-ish as this.
You do realize that posing for a photo doesn't equal having sex right? You don't know anything about this girl, who she does or doesn't sleep with, or what sort of protection she uses when/if she does have sex. All you have are assumptions you made when you looked at a photo you don't approve of.