Let me offer an example. I have a pair of friends who are both PhDs in CS, and both work at Google. They have a daughter whom both parents would love to see in engineering. The mom has the following story of when she gave up trying to resist her daughter's inclinations to make everything pretty instead of wanting to build stuff.
Mom left her daughter to play with a box of regular legos for a bit hoping that she would try to build something. When she came back a few minutes later, every green lego was out and a smattering of others scattered over the floor. Her daughter looked up with a big smile and announced, "Look! Here is my lawn, and these are the pretty flowers!"
I have watched this with my own daughter. First, let's be clear, we do not have a TV in our house and she does not see most of that marketing. But everything "girly" that she's been exposed to, she wants. Why? My best guess is that she's keenly aware that she's a girl, she's not a boy, and she actively seeks out clues as to how to not be a boy. At preschool she gets exposed to the idea of what girls play with, and she's happy to go along.
That is in her case it isn't a push from the external environment to be that way. It is a pull from within herself to figure out how to conform.
Whatever the cause, the extreme girl toys you hate are in the store because they sell. The marketing that you hate is done because it works.