That person is just on a personal mission right now. Once he has achieved his internal goal, the space for leisure will start opening up to him. People who like video games, but are on a mission about their new thing don't really feel like they want to play video games, even though they played them a lot in their past for example.

Also some people are just missing things neurologically that make certain things compelling for most people. Some people just don't care for music much because it doesn't do much for them and concerts are kind of confusing enjoyment wise. Same with many people in software for watching sports, they're just not that into it.

For others, it moves them greatly. Maybe he doesn't create the internal world required for fiction when he reads fiction.

So either he is on a mission (people who are noticeably good at something tend to be) or they are just missing the thing that would make it enjoyable for them.