Why the absolute decimation of progressive radio?

Before 2003 I was pretty much apolitical. It wasn't that I didn't care, it was that I knew since the 60's that the process was totally corrupt and didn't reflect the wishes of the majority of people.
At that time I looked for any and every source of information to get a more realistic perspective on world events. I found so many sources back then that I could spend the whole day listening to them. Of course, I had to listen to all of them on the internet. Those that had a terrestrial base lost stations that were either bought out or changed format. The changes resulted in really serious loss of media share.
Some of the shows, a small percentage are still available but they aren't on commercial outlets.
Those on listener supported stations are mostly there but the cost to keep them on the air means fund raising every other month. Others have gone to internet only which means that the people who need to hear the discussions might not have the capacity.

I've put up money to keep some of these outlets going but it's really tough for an old man with no income. Why are there not more people willing to pony up to get voices that get more facts in the discussion a wider audience?
Is it really a smart move to walk away from terrestrial radio? Seriously? It's the lowest common denominator. You can be poor as dirt and still buy a radio to get your news and information.
The so called "conservatives" learned in 1971 that they had to build an information infrastructure to support their ideas. Isn't it time that we learned to do the same?