I agree it is what the parents put in front of them. My child watches PBS and Disney Jr only. Because that is what I put in front of her. She has seen some of he classics and some of the newer stuff. We are slowly collecting Disney, Pixar, Dreamworks, and other kids movies like DM. Once on she prefers some shows/movies over others. Like she is not a fan of all of Lion King, but can't get enough of DM. She likes Cars when we are in the car, but if we play it at home, she wants nothing to do with it. Odd and can't figure that one out, because when we give her a choice of three movies in the car, she will always pick cars, unless DM is an option. We were at Best Buy and she watched the same clip of Madagascar 12 times and I had to pull her away, so we are going to get those films too. Shrek she is just OK into. So she is all over the place really. BUT there are many programs she has never been exposed to that are VERY popular. Because I don't care to watch them and therefore she does not watch them. So saying what your kids do or do not like, is not really showing what other kids do or do not like.
Oh, and my one friends has a 5 year old that goes to Disney every year, loves it, asks to go, etc. And has seen none of the movies Disney has put out
So movies/shows is no reflection on whether the child will or will not like the parks itself.
Oh, and yes, I live in Florida and this probably means more Disney merchandise, but the one type of shirt I see the most in my kids daycare class? Mickey and Minnie shirts. The one day three kids had different Mickey/Minnie shirts and my daughter came into the room all the kids made a big deal of her Minnie shirt. I have not seen the same reaction or trend with other IPs.