I'm not sure he said that it must enrich you or it isn't art. His point was whether or not the effort one puts into a particular thing saps or uses up intellectual intelligence of a person. Is the task a hamster wheel where no benefits are experienced by anyone other than the hamster or is the hamster wheel connected to a capacitor and providing electricity to the other hamsters. I don't see a reason to get into the elitist arguments. All of these activities fall somewhere on the spectrum of the amount of good provided to humanity. Closed loop activities that only recharge one's battery provide less benefit to humanity and can be said to sap or use up our intellectual intelligence. There is no elitism about this argument, it's just a 30k foot view of us hamsters and which ones use more or less intelligence that benefits the rest of the hamsters.
Get off your Silicon Valley, always got to hustle hamster wheel. Go watch a sunset.
I don't see him saying that, or even implying it. Rather, he seems to be indicating that is a valid vector by which the activity can be rated. It is not the only thing it can be rated on, nor is it even necessarily _worth_ rating it on that. But it is a thing that can be discussed.
Fiction can have the potential to broaden knowledge if only by making writers doing some research.
First off, everyone needs fun hobbies to distract them from their day to day. While many gravitate to hobbies similar to their career, it should never be a requirement. Its whatever recharges your batteries. However you achieve that, whether chess, reading, woodworking or nature walks, it doesn't matter. Again, as a fiction writer, the academic elitism of it really pisses me off. Not all entertainment needs to broaden your horizons. It first has to entertain and make you lose track of the miserable real world. Teaching you something is second on the list. Not first. Shoving the "it must enrich you or it's not art" is the most heinous elitist gatekeeping there is. This is the exact reason people dont like reading. Being told, "you're not reading the right books" turns people off, thus will never read said books.