Stay at home moms!

Why are stay at home moms looked down on? I here things like "A real women makes her own money" or a feminist told me stay at home moms are the reason we still aren't seen as equal to men and that they should be forced to work. I'm not a stay at home mom yet but when my baby is born I would like to be. My husband says he doesn't care if I work or stay home. I just don't trust anyone to take care of her the way I would.