Don't recall anyone acting "rabid" on PBS. That sounds like a personal problem you have with detecting reality.
The OP has bought in to the strategically pedaled theory of Leftwing media control. Where did this conspiracy theory come from?
Nixon invented the liberal media conspiracy to get the press to stop investigating his crimes. Nixon famously called it the "Jew run liberal media."
Starting in the 70's, the Right used the "liberal media conspiracy" as a partial motivation to launch their own universe of media outlets fed by a well-funded assortment of think tanks. This interlocking institutional structure gave them a
protected space to manufacture facts and arguments that served their political goals, i.e., a space outside the confines of traditional oversight.
But seriously, why did the right launch such an aggressive media revolution in the 70s; why was it necessary?
Answer: You have to remember that during the postwar years the Republican Party had a large block of centrists. The rightwing of the party was in the wilderness; their challenge was clear: they needed to create the ideological conditions for
unmaking the New Deal / Big Government consensus. They needed to move the country right and purge their party of centrists. They needed to move the goalposts so far to the right that even PBS would look like a Marxist conspiracy. But they faced a tall challenge; their party was controlled by iconic centrists like Rockefeller and Eisenhower - both of whom, by Tea Party standards, would not be permitted into the current Republican party. They needed to change things, and they did
But how, specifically, did they win the loyalty of the Americans whose minds they were trying to change?
Answer: they used the culture war as a strategic populism to attract a certain kind of paranoid and under-educated voter. By appealing to their conservative identity, the power structure on the right captured these poor souls and they conditioned them not to trust any news outlet but FOX (or its variants in print and radio). The revolution fed upon the minds of people with little to no advanced education, i.e., people who didn't know enough about world history & geopolitics to question how they were using the Cold War (and later the War on Terrorism) to remake the global and domestic economy to favor the ultra narrow accumulation of wealth and political power, that is, they needed people who were easy to fool, people who knew as little about the Sandinistas and Contras as they did about Bin Laden and Hussein or oil geopolitics, i.e., people who would not question what they were told.
The biggest lie - the one most crucial to their maintenance of power - was about how the liberals had stolen their government and their media and their entertainment ...and their financial institutions. They used the "liberal media conspiracy" to lock their base in a hermetically sealed information bubble. Inside the bubble these poor morons were terminally agitated with color coded terror warnings over manufactured demons .... gay, islamic, mexican, secularist, Saul Alinsky, hollywood, illegal alien, blame America first, Saddam Osama Saddam Osama... Marxist socialist atheist islamo-fascist demons.
And so yes . . . they were told that PBS was a secret wing of the Marxist conspiracy to take over the country.
(and they bought it)