I am a middle-aged, second-generation granddaughter of Czech immigrants. I grew up in the old, European-influenced environment where familiarity with classical music was part of cultural literacy. At one time, I was actually a full-time student of classical music, and I worked for awhile in stage management for Cleveland Operat Company. Now I am a St. Louis Symphony patron and also serve with the orchestra's volunteer association.
Your article seems to include most if not all of the changes in the public's and the media's approaches to classical music during the past few decades. The phenomena you describe have troubled and saddened me. I have thought about them a lot.
I would suggest a couple of causes. First, I think the reorientation of US awareness from its (earlier) European roots to a more homogenous, media-generated culture has resulted in what I see as an impoverishment. Most cultural awareness seems ultimately generated by advertising these days.
Second, I think the 60s made people paranoid of having strong views on anything. There is a certain amount of spillover from the desire to be PC and not offend that reaches areas far distant from abortion, race, and other hot-botton issues. We have become a nation on tiptoe, fearful of offending the strangers next door. Such a climate does not foster vigorous debate.
Thanks for laying out the problem.