You don't really need a critic to see that it has spread everywhere. People not just adore, they demand to be given a three paragraph summary and a moral of the story for everything, no matter which era, which genre, or how much magnificent embroidery was presented to them. So-called Web 2.0 review platforms have succumbed under the weight of people complaining about not being given clear instructions by the authors, and people trying to invent those clear instructions on “understanding” the work themselves. It seems that the simple truth that the whole point of work of art is how it starts processes in your very own head is a secret which is well hidden from those who expect that others can do thinking in their stead, and just state the “results”.
Of course, from that perspective, modern society hasn't changed much for centuries, they just had different excuses back in the days. However, it doesn't happen by itself; the construct of the presumed movie-goer (or reader, or listener) affects the public. When author has high expectations of a recipient, many of them can find themselves growing to that level, when the lowest common denominator is targeted, everyone's average drops. Writing by committee and directing by committee inevitably results in watching by committee, when no one cares because there is enough ways to find out which opinion you “should” have about the movie, and the only thing left is to check the box for visiting the cinema (the obvious democratisation of an old cliche of rich nobles being bored at the opera).
A lot of auxiliary apologetic nonsense is written about “pop culture” today — its “consumers” need to be told how to look at themselves. A vaccine against that would be finding something so bright and delicate that it can't be stuffed into one of predefined expected reactions. A lot of much stronger criticism have already been written, too. One might point to such “hits” as Vladimir Nabokov's “Strong Opinions” and lectures on literature, although the suit of renowned writer and lecturer was perhaps a bit too bronzy, while in reviews read by a small circle of Russian-speaking emigrants in Europe (collected in “Think, Write, Speak...”) or in satirical passages in fictional works he was a bit more open.