Wow I love how many people replied to you here. For me it's painting, acting, meditation, yoga, guitar, and lots of broad interest in media that aren't so conformed, like foreign, old stuff, etc.
As a software eng who has always had a lot of hobbies, it's almost alienating how so many people in the office are only into TV shows, super hero movies, sci fi books, video games... It's like, there's a whole world out there people!
It's possible he was echoing the callousness by not expounding on it. I don't think word count is the best way to measure importance in literature. Understatement is a tool authors use.
Haskell actually could help a lot with JavaScript. Functional programming, writing stateless functions, function parameters, and generally manipulating functions, are valuable and useful concepts in JavaScript and React, and Haskell forces you to learn and understand them. Alternatively, F# could fill that niche if you prefer its syntax.