Things I don't understand

So, here I was online, innocently playing a game of solitaire, when some random guy IM'd me. G: Nice tits! V: Thanks, but I'm not interested in talking to males. G: I don't know why you even have a profile. Your outfits are false advertising. You're nothing but an ugly, fat-assed, saggy-titted bitch! V: Um, whatever. (place on ignore) I just don't get it. This whole thing is anonymous....why not just take rejection gracefully. There's really no need for a verbal slap in the face. Yet.....at least 35% of the time I politely reject a random guy in IM or e-mail....I get comments like the above....somehow by virtue of my rejection, I've gone from "hey great tits" to "you fucking bitch"....