Amy Goodman is not on many "public" radio stations. She's on Pacifica and Pacifica-type community stations run out of donated garages by whackos.
As to the free market's interference in radio, who would you like to have run it? I agree CC and others may own too many stations in any given market, but whether they have ruined radio or not, if 11,000 or so radio stations were run by 11,000 or so individuals with only enough money to own one station, we'd have the personal views of a lot of nuts on many of those stations. Just look at many cheap, poor-signaled AMs owned by individuals in this country. How else do you think the Genesis network gets cleared?

She is on many taxpayer-subsidized Pacifica radio stations; also, Goodman finds her way on college campus radio stations, which are mostly taxpayer-subsidized (private colleges also take public financial aid money, which is also applied to the Student Activities "tax" that helps find these stations. Also, many of them receive direct government grants to run.
While it shuold be okay in America for Goodman's propaganda to exist, why should the taxpayers have to pay for it's survival?