Really, I have the opposite with my son and daughter... Neither cared anything about HP books, maybe the first movie out of curiosity and now at 20 my daughter has reverted back to the princess thing. My son (16), hated the HP movies, they were boring to him so much he refused to see the last three while the SW EP I, II and III and TCW television series were exciting to him, we have to ride Star Tours 5-6 time each trip to DHS. I tried the last three trips to get them interested in USF/IoA with zero luck. On top of that, we have six roughneck totes heavily payed with SW action figures, ships, Lego's etc to boot.
My children are by no means the only ones in my area that showed little to no interest in HP books or movies. Around halloween, look at the costumes that pass by your door, how many are Disney Princess/SW/Marvel vs HP. In my neighborhood most of the girls were Disney Princesses of some kind, or just a princess, with a lot of Marvel/SW with quite a few clone troopers and Darth Vaders.
IMO, when people plan a big vacation they go to Disney World because of the classic rides, the stable environment. When they want the latest, fastest thrill rides they go to Six Flags or their local theme park, they might plan a day or two excursion to USF/IoA but I have yet to hear anyone planning a vacation around USF/IoA even with the extreme amount of advertising they are running.