Lots of it.
Consider that atheists get a couple hours a week of radio and television airtime, whilst religious programming in the USA in print, radio (including shortwave), and television runs into the hundreds of thousands of hours a week.
Try to get the FCC to approve a license for an AM Talk or Shortwave broadcast station where the thrust is secularism and atheism. FCC licensees have to show there is a public interest in their broadcasts and it serves the public interest to have a station. They also have to show the station is financially secure and have a business plan (so the station doesn't go dark).
Churches and religious organisations are awash with cash, atheist ones are not, so the FCC could reject a license on that basis alone. Vicious circle: no broadcast without money, no money without broadcast.