The question to the subject title is: because their parents made them. Same with why young boys tend to lean towards blue, red or green. It's because most people, even those that are not parents, have these preconceived notions embedded in their brains by society that girls should like pink and boys should like blue. Also, girls should play with dolls and boys should play with toy trucks. A generalization? Yes, but it is mostly true. In fact, I wrote about this on Re:Generator Magazine* based on an article posted on the UK's Telegraph news website. The opening two sentences of the article sums it up pretty nicely:
Experts have claimed that the so-called "pink plague" on the High Street is brainwashing girls and reinforcing gender stereotypes.
They claim that girls are already becoming "hooked" on the colour before the age of three and soon reject toys and clothes if they are not pink.
This doesn't help my gender growing up when some girls grow out of the pink craze and choose to pursue things that are not considered feminine. Boys will make fun of a girl who wants to play a masculine sport, or even if she wear jeans instead of shorts, skirts or dresses. I know, it's happened to me.
