There's also an alternative explanation.

It is hardly unusual that new music is often dismissed as inferior by the older generation. My parents thought the Beatles and such were a poor substitute for Tommy Dorsey, Frank Sinatra and the others they grew up with. Remember that Bach was almost fired from his first job as a church organist 300 years ago. The church elders thought his weird playing was distracting the congregation.

It's really pretty standard stuff throughout history that new artists and composers are often reviled by their elders. It's hardly news that there's a lot of new music that middle aged audiophiles don't like. (And yes, there are always exceptions, but we're talking general trends here.)

Now, combine that with the trend of falling CD sales for the past 10 years (CD sales are about one-third of what they were in 2000) and you have a modern generation that simply isn't buying music the same way as prior generations.

As such, it is no surprise that "catalog records" (i.e., the old stuff) is now a high percentage of sales. They are reselling new copies of the same music to old customers at cheap prices.