As much as I am a massive, MASSIVE supporter of art programs in school (creative and psychological benefits ftw), I will defend football and basketball because those are popular sports that people like to watch. They charge money for tickets and it brings in revenue for the school. Besides, once you get all the equipment, it's relatively cheap to keep up the program.
Maintaining art classes and supplies, however, can be enormously expensive. :/ Now that I have to buy all these supplies for my degree, I can see why they would get cut, sadly. Luckily there are programs like ArtsBridge that will teach art in schools for free or a very small price. I taught third graders when I participated in that program. It was great!