> I’ve never met a person saying they hate books and wish they were white on black.

That's because paper used to print books isn't always white. Most of the books I've read this year and last year had a somewhat yellow-ish tint to them (they were newly printed). I know I'm not the only person bothered by pure white paper in books.

I absolutely agree about setting brightness correctly, though. It's very usual for me to instantly reduce brightness whenever I have to use someone's computer. No idea how people use their screens so bright.