I know this is likely going to lead down a rabbit hole, but what the hay...
Pirates of the Caribbean, "it's a small world", Haunted Mansion, Space Mountain, Matterhorn, Big Thunder Mountain Railroad, Jungle Cruise - all "classic" Disney attractions that have been around for decades and all of them well regarded and popular. And none of them were attached to or based on an IP.
It's not that Disney fans don't like attractions based on popular Disney IPs, and its true the parks have always been a way to promote Disney films and stories. But I think there used to be better balance between IP and non-IP. Nowadays just about every new thing at Disney Parks® is attached to an IP and many fans (me included) think that's unfortunate.