The windows 9 thing is why Windows 16-bit subsystem is v 3.95, the OS/2 version is always 2.xx (eg Warp = 2.30, vers 4 is 2.45), and do forth. It's just that the vendors write code to test for the first character, or assume windows 3, and test for > 09 (ie 3.10. 3.11).
It is in the interest of the OS manufacturer to whizz through the numbers, but the ordinary plods are going to look for the current version +.
I mean, vista, seven, eight and eight-point-one, are logically 6.0, 6.1, 6.2, and 6.3.