Because it’s easier on the eyes. For people spending unhealthy amounts of time being bombarded by monitors right in the retinas, it’s a necessity.

Black text on a white background actually causes less eye strain esp. for people with astigmatism because the text is easier to read.

https://ux.stackexchange.com/questions/53264/dark-or-white-c...

It's not a "necessity," it's a personal preference.

I started out programming on a dark theme (the emacs default) but I've used a light theme professionally for about 15 years (and no other dark applications). I prefer the light theme and I don't find it hard on my eyes one bit and I have astigmatism.

The Emacs default is bright (black text on white background), not dark.

The exception is if you're using it in a terminal, in which case it re-uses the terminal's colors.

Well, the emacs theme installed on our school computers was a dark theme. This was way back in the day.

Probably because all true hackers sit all day long in a dark underground room, lit only by the dim glow of their monitor refracting through puffs of cigarette smoke.

Or blue. It's cool. It's what the cool hackers like,accept it! :P