Earlier quoted context omitted.
The bottom line is that older music seem better because time is a filter - we remember the good stuff. People have always complained that "music nowadays" is crap.
There is a hypothesis that older music seems better because it is cherry picked, and is being unfairly compared against a random selection of new music. That hypothesis is, unfortunately, starkly false. Music nowadays really is crap; time is not helping it. If we use our 20/20 hindsight and pick the best music of, say, the past 50 years, it will be heavily weighted toward the first 20 of those years. Thirty years ago…
OK...why do you think is it false? That you don't care about contemporary music doesn't really disprove it.