I'm not sure what 'evidence' would be satisfying to you for something like this, but maybe something about the man himself will help you understand what he means?

https://www.newyorker.com/science/elements/after-years-of-ab...

tl;dr for the article: “Please just kill yourself now. The world will be a better place” - Linus Torvalds, former "Candid" speaker