Because they're deranged control freaks who need to convert a single character that is semantically a tab into multiple characters that are an opinionated representation of a tab.
Devs: We need to separate concerns and split the view from the model.
Also devs: Someone might view the code differently!!1!
A codebase that's formatted notgivingashittily is an accessibility issue. It's not just deranged control freakism.
Maybe Yelp's codebase was otherwise clean, but aside from golang projects (and the Linux kernel) I've come to associate tabs with unreadable slop code. Maybe your experience is different.
Forcing a single opinionated tab width is an accessibility issue -- a real one, not a weird heuristic that boils down to "tab fans can't format". I've read multiple accounts from people who need either very small tab widths (to accommodate unusually large font sizes for eyesight reasons without cascading off the side of the screen), or very large tab widths (to accommodate difficulty in seeing indentation differences, again for eyesight reasons).
I'm confused. how does handing control of the reading experience over to the reader = accessibility issue? isn't it the other way around? accessibility issues come in many different forms, and you can't accommodate them all yourself.
Devs: We need to separate concerns and split the view from the model.
Also devs: Someone might view the code differently!!1!