Here, courtesy of Jezebel, is a little girl ranting on the pink ghetto and product-aisle insistence on her ascribing to the Princess Phase.
Interesting how she trips over how boys don't want to buy pink stuff (she was going to say that they did, but it rang false to her) - her dad "corrects" her, but we all know the Pink Ghetto exists beause "pink is for girls and NOT for boys." She seems more confident when she says that boys might want to play with princesses.
So, for the record: all girls do NOT want to be princesses. Instead, consider that 3-5 year olds want to emulate adults. Unfortunately, this means marketers give girls props to play at being a mommy or a princess (most marriageable maiden). Queens are typically evil, and why boys can play/explore other aspects of daily life (cities, farms), girls' props are usually confined to the domestic. So to repeat, girls just want to practice being adults, the same way that boys do.
Clearly there's a gigantic business opportunity to simply re-package non-domestic daily props in pink boxes. Throw some sparklies on there. Excellent: now you've got a pink microscope and chemistry set, pink road construction toys, and let's throw in a pink tool belt, presumably with sparklies. Then wrap princess costumes, vacuum cleaners, and baby dolls in boxes of bright primary colors for the boys, and you're done.