Based on the other comments I thought this article would be suggesting that there's a new trend taking place with people in their 30s. The author does seem to be trying to position it as "hey look at this interesting phenomenon" but doesn't actually claim that it's new in any way.

So basically: we're becoming our parents, or repeating a story that every generation goes through. Personally, my parents had piles of records from the 60s-80s but didn't listen to that much music. I do listen to a few hours of music each day, including whatever new stuff I can find, but it's mainly work noise to cover up other sounds.

Some of the declining interest can be likened to comedy. When you're 15 or 25, there are a lot of jokes you haven't heard before. If you're 35... or 65... certain routines start sounding pretty worn out. With music I suspect there's also a social learning component: we fall in love with music when we're young and still trying to find our place in the world. Music tickles the same communication centers in the brain that are used for social positioning, and the value of that, also, fades later on.