Personally I do not see it that way. Yes I am a fat chick... but I will not lower myself to that level to get attention. It's those same people who have those kinds of pictures on their profiles that wonder why guys only want sex from them... well DUH when you put that out that's what you get back.
I want more than just sex from a relationship, sex of course is part of being in a relationship but I don't want to be used by random people just for that.
There is more to life than that. Maybe I am reading more into all the nekkid pics in these profiles than there is meant to be but that's how I personally see it. Fat chicks don't need to lower themselves to get attention, The right attention will come maybe not right this second but isn't something like that worth the wait?