That's an interesting observation. Unfortunately, I do think there's aesthetic-preference profiling. I also think it's both natural (through a natural desire to procreate the species - equating good-looks with health, therefore producing healthy offspring) and acquired means (mostly through advertising - sexualizing people to sell a company's products). People are attracted to what they would consider to be good-looking people, and are probably kinder to them than they would be to those who are seen as not as attractive.
So, to answer your question; Yes, I think guys are generally nicer to pretty women. For the same reasons, I think women are nicer to good-looking guys.