I'm here, and the family's all retired. There are parks like Western Playland in Albuquerque, Amarillo and Lubbock. They're small parks. Old Tucson is now starting to add some rides, too. El Paso's per capita income is low.
People can only spend so much on entertainment.
They're going to go to the most inexpensive place. Magic Landing was trying to be a theme park. El Paso wasn't really ready for one. It doesn't have the population or the family income levels to support a theme park. When people go on vacation, they're willing to spend extra money on theme parks.