I think people underestimate the effect that is had on children when they're told "that's not for girls/boys". It's fine up to a certain age but at some point they get self-conscious.I don't have issues with this,my kids have all had free reign of which toys they want and I don't care if they are pink/blue/luminous yellow,they are just toys.Everything has to be labelled these days.
I remember feeling crushed when some stupid boy told me I couldn't play football cos I was a girl, and this was at the age of 7. No matter how much of a confident child my parents raised, that kind of thing goes to your head.