Maybe, but the news programs are only a part of the networks which are only a
part of the companies which own them (see Disney-ABC-Peter Jennings), and the
conglomerates act like rational capitalists. Leaves the question why they
allow their news shows to inject such editorial content. I think it just crept
in over time and only now with other sources showing the loss of viewership
will they realize the folly of their lax oversight.

The reasons the networks aren't rational capitalists is because they are
liberally biased (that is: liberal). They cannot reason and driven by
self-loathing. Liberalism is the result of one or more mental disorders. In
our capitalist economic system they will suffer the rational outcome of
their bias - they will go belly up. The financial momentum of the news
leviathens just delay the day that they become fertilizer.