I think manojlds point is why the OS names are not sorted by the first word in their name as opposed to the last word in their name. Microsoft Windows should have come right after macOS, if the list was sorted alphabetically by first word, then last. It must be sorted by last, then first though. I guess it is a bit of a strange choice since most OS distributions seem to have a single word for their name, making Microsoft Windows appear miss-sorted.
Windows is 100% in the bottom not because of the name but because it is proprietary. The author of the website (Drew DeVault) is a devout FOSS proponent.