Why don't they put more emphasis on PE in schools?

When I was in elementary school, they made us run around the track a mile-and-a-half every day. They did the same when I attended middle school in the early 90's. Then my senior year, I took bowling for PE. What kind of strenuous exercise is that? Why don't they make all kids do it? The obesity pandemic in America doesn't look like it'll disappear anytime soon. If it were up to me, sugar and white flour would be banned from all public schools. So would soda machines. So why don't schools make kids take a real physical education anymore?