Thank you for such a thoughtful questions! You're right that reader or viewer demand (in the form of, say, Nielsen ratings for TV) does play a role, but it mainly affects smaller issues: low ratings can cost an anchor his or her job.

Politics and economics play a much larger role now than reader or viewer demand, especially the abandonment in the 80s of something called the Fairness Doctrine, which required stations to present opposing points of view. Combined with the rise of cable TV, that killed any hope of balanced reporting.

Yes, we absolutely need more independent voices. There's little hope of getting them in TV (it's too "siloed"), except in great independent features like the PBS "Frontline" documentaries.

But in print journalism, an encouraging sign has emerged in the rise of independent news websites funded by grants or noncommercial interests. Keep your fingers crossed that something similar will happen in TV!