Why do people think that..A&F, Hollister, AE, Aeropostale are all "fashionable"?

Okay so what's up with this? I see all these..girls on Y!A talking about how cool it is? Have they NOT seen real fashion? ( Chanel,Gucci,Prada,D&G,Valentino,YSL? ) ...I mean it's really just the same thing over and over again. "AE 1939" "Hollister 1835" " ...it's so expensive too. Please no negative comment, just explain your opinion on this haha :]