All non-commercial radio stations run by not-for profits. They don't answer to advertisers or deal with PPM ratings.
Radio would be a much different place if it wasn't for advertisers. They're the ones who insist on formats that attract certain demographics and achieve certain ratings. Eliminate them, and things become different. The problem then is who pays for radio? Listeners through subscriptions? Taxpayers? Somebody has to pay the bills. Thankfully, there are some educational institutions in your area that have enough money to cover the costs. For now.