Because we're fashion! Look at Paris Hilton, she's seen as thick, and only lives off her dads money, but... She only had money off her family until she started work, now she's a self made millionaires. Why do people think she's thick? Fashion!
Many see fashionable people as having too much time so they spend it on fashion.
Our jobs are seen as easy, play with hair, paint on some colour and cut a straight line. Yet most who think that can't cut open a bag of frozen veg.
Don't let it bother you.
And btw, I was a stereotype. Blonde, hairdresser, gay, wore the latest fashion and I wish I still am, but I was thin. Did I care? Hell no! I love me, and that's all that matters xoxo