Ok, so the half-time show used to be stuff like marching bands because the NFL liked to keep it cheap. But while people stayed on the channel airing the superbowl, few actually cared about the show. Take a piss, grab a drink and snacks. You know, break time.
Then in 1992 Fox commissioned the Wayans to do a special episode of In Living Color to be aired live during the halftime show as counterprogramming. And it worked like gangbusters, and like 25 million people switched to Fox to watch the special instead of the halftime show, a 22% reduction in viewership.
The NFL saw that shit. Didn't like it. The next year they booked Michael Jackson, and the rest is history