It's always surprising to me that smart people end up learning this lesson the hard way. Users want stability and slow evolutionary change the vast majority of the time.

But, I think the motivation here was a bit different, canonical had less control and influence over the desktop than they felt they needed.

I would agree with you if it wasn't the case that you can easily switch to "ubuntu classic" which is very similar to previous desktop experiences. Also I'm not sure if upgrading from 10.xx to 11.04 takes you unity or to ubuntu classic, it should be to classic in my opinion.

full disclosure: I'm a 10.04 user and plan to stay that way until the next LTS.

But "easy" is relative. To geeks like us who know to search Google with "how to replace Unity" (a phrase that would never, ever come to mind to Grandma) and know that we just have to change a dropdown setting, it's easy.

If you tell a "regular Joe" user that by clicking a dropdown you can change how the operating system fundamentally works, they'd probably think you were lying--the thought is that alien to them. There's a slim to none chance they'd discover that option on their own (not in small part because they wouldn't even know the option existed), and an equally slim chance that they'd know how to search for it.

To you and me, "Unity" is the "well, duh" search term. To regular people, it's tech gibberish.

So again it all comes down to the average user--they don't like change, they don't keep up with Ubuntu news, and they aren't interested in fiddling with configuration options to have a usable desktop. I don't think that you can have both fundamentals-shattering releases and also a ppa-based/milestone-release distro at the same time.