I don't think people are making decisions about their UI colorschemes based on ergonomics. As a rule, people who say they use white-on-black or black-on-white for reasons of comfort or health are just rationalizing an aesthetic preference.
(n.b. I'm not weighing in on whether one white-on-black or black-on-white is more ergonomic, I'm just saying that it's rare that someone preference is actually grounded in ergonomics)
There's no shame in having an aesthetic preference, nor in sacrificing some ergonomics to realize it. If people always preferred ergonomics to aesthetics, everyone would be wearing New Balance shoes (I'm a happy owner of a pair). Your system UI and your code editor is something you stare at a lot, and it's reasonable to want it to look good.
(n.b. I'm not weighing in on whether one white-on-black or black-on-white is more ergonomic, I'm just saying that it's rare that someone preference is actually grounded in ergonomics)
There's no shame in having an aesthetic preference, nor in sacrificing some ergonomics to realize it. If people always preferred ergonomics to aesthetics, everyone would be wearing New Balance shoes (I'm a happy owner of a pair). Your system UI and your code editor is something you stare at a lot, and it's reasonable to want it to look good.