It also clearly says "2500 radius circle" in the article title, and the submission title. The article is fast and loose with diameter vs radius later on as well. I can't blame the original commenter for using it as a radius when that's in the title.

But I agree, it's actually the diameter and changes the math a lot.

The distance from Mumbai India to Osaka Japan is ~4000 miles. Both of which are clearly inside the circle.

What are you using to assert that the 2500 mile number is the diameter?

This actually fits with the visual impression you get from the map. It's clearly far less than 50% of the inhabitable land mass

Yeah this is the error in the parent calculation