> Every new version of MacOS exhibits four phenomena:

This is specific to almost every new software.

As jwz said "But that's what happens when there is no incentive for people to do the parts of programming that aren't fun. Fixing bugs isn't fun; going through the bug list isn't fun; but rewriting everything from scratch is fun (because "this time it will be done right", ha ha) and so that's what happens, over and over again. "