In the linked case, I'd argue that specialized fonts or editors are a better choice. After all, even if you make all the code in your repository "accessible" by using tabs, your accessibility-limited colleagues might have to interact with code outside your repository (e.g. Stack overflow, or dependencies) that uses spaces. Something in the presentation layer (e.g. fonts or a screen reader) is far more likely to work consistently and correctly. Solve problems at the right layer.

That stated, I can see why such an objection might win the day. Nobody wants to take on the accessibi problem when solving a small problem like spacing consistency.