Reading through your post, I noticed that it parallels the 'even-odd' rule for Windows, while pointing to the reason. Starting from Win95 (which was a complete-ish do over and the first Windows that was actually an OS), the "even" releases are the ones that work on user-facing polish. This includes stability, bug fixes, responsiveness, efficiency. This does not include back-end architecture rewrites, server capability etc. These are the ones with a great reputation.
Notice the "odd" ones are 2K, Vista, Windows 8. These are the ones where major, major stuff happened behind the scenes. The result of this is that fewer resources were devoted to making the user experience really awesome. And that's why they "suck" even though they have significant technical advantages.