Journalists these days are generally
not hired for their incredulity. They're hired based on a track record of not deviating from their employer's political and financial priorities, regardless of the evidence. These are businesses, not public services. They owe their existence to dishonest and manipulative presentations of the qualities of third-party products that they sandwich between their own content.
Lets go back to the days where media outlets were open about their editorial stances, rather than hiding them behind a veil of white-coated objectivity. Propagandists should stop pretending to be doctors, and just be honest propagandists.
Putting it all on Democrats isn't completely fair, although I get how bitter Silver is that they sanctified him when he told them what they wanted to hear and condemned him when the data pointed the other way. It could have just as easily been the Republicans in control of those institutions now if the party weren't so hostile to minorities.
That hostility cut them off from dominance of the nonprofit sector, which serves to convert the money of governments (i.e. the will of elected officials) and oligarchs into media messages. They're stuck with thinktanks and veteran's organizations, although they sometimes find openings in patient's rights nonprofits (run by pharmaceutical companies.)