I don't think anyone's disputing that 'sex sells' and the idolization of physical beauty has long been a social component. Again, though, the whole notion as it applies to A&F begins to take on water when we look to other companies that are also almost wholly reliant upon sex appeal to sell their products - like Victoria's Secret - who do not seem to operate with such blatant exclusivity. Yes, we all know that only the Angels will look like the Angels in the clothing, but that sure doesn't stop VS from hawking it all with strong appeals to glamor and sexiness to eager consumers of varying sizes, and it certainly doesn't stop said consumers from buying it, year after year.
I maintain that there is a difference, as Stephen said, between companies utilizing people deemed "conventionally beautiful' for commercials and ads and even catalog modeling, and declaring - making it a cornerstone of their brand, even - that they do so because to use and sell/cater to anyone outside of their stated paradigm incapable of 'belonging' to and in their label is unacceptable. And worse, still, is the reason why, that they offer - which is that they hold that everyone 'incapable' is too physically unattractive.