@robpike @timbray funny, I was going to go the other way, only because the bright backgrounds tend to be more annoying to me, so I often opt for darker themes. Of course, being the fickle person I am, sometimes I'll let an app or OS switch based on time of day or ambient illumination levels.
That's all on an emissive screen, though. A *mumble*Kindle*mumble* I like light when there's light and don't need rear illumination, but definitely prefer inverse in the dark.
@emag @robpike @timbray you can't just say "white text on black background" and expect instant readability. You need to consider overall brightness, contrast, sharpness, light bloom and bleed, specific color palette, and even font and letter size.
A lot of so-called dark themes don't do this, and instead just pick the path of least resistance. As a result they look horrible and cause eye strain on any bright 23" LCD, especially in a dimly lit room.