Sure, I guess my question is around why people would consider a line in a sea of space more legible than the same x-height font with less space below it.

I guess I could have an unusual take on this, but I find a lot of mono fonts seem to have massive inter-line spacing. So much so that their appearance is almost jarring to me. I find it disruptive to read. If I had issues with the legibility of a font then I'd increase its size, not the spacing between lines.

As mentioned earlier though, I guess I'm an odd-one-out here, I'm seeking to understand how/why my view here is unusual.