I never bought this argument, because it seems the vast majority of people are fine with viewing tabs rendered as four spaces. And pretty much the default for spaces is four spaces. So I'm starting to think 99% of the world uses 4 spaces and it's the vocal minority that like 3 spaces or 5 spaces viewing for tabs. And in that case, the configurability is rather irrelevant.

Until you are visually deficient. Then it matters a lot.

Accessibility is not a joke.