> Right wing media has been around for decades
Not really, right wing media (as we know it) came about precisely because of this problem. Rupert Murdoch created Fox News in 1996 because it was becoming increasingly clear that the erstwhile media had moved in a direction that alienated a broad section of society. This marked the end of the Walter Cronkite era.
As for why this started in 1996, and why the Walter Cronkite era was so tranquil, I read one theory on a recent interview with Patrick Collison (https://noahpinion.substack.com/p/interview-patrick-collison...) which shows a consistent pattern:
"Culture. As Ezra Klein recently described in the New York Times, and Marc Dunkelman has written about in his great piece about Penn Station, a particular version of distorted, hypertrophic progressivism that took hold in the 1970s may have had (and still be having!) quite significantly stifling effects. We perhaps shifted from placing emphasis on our collective effectiveness in advancing prosperity and opportunity for people to the perceived fairness that was embodied in whichever particular steps we happened to take. Or, to say that another way, we shifted our focus from sins of omission to sins of commission."
This "hypertrophic progressivism of the 1970s" was broadly started in college campuses of the time, and by around the late '80s and '90s, college students from the '70s were beginning to find themselves within the ranks of leadership in most of our institutions.
> So again I ask, what's the problem?
The problem is the perceived impedance mismatch between professional institutions (media, white collar corporate America, etc) and society at large. Because this is an issue that has existed since at least 1996 (the advent of Fox News), the assertion is that the root cause is ideological movements that begin on college campuses that have historically not aligned with the ideologies of broad swaths of society; and adherents of those ideologies eventually going on to run our professional institutions.