It seems inevitable that any given project has the potential to reach a point where the critical mass of users find it satisfactory. Perfect? No. But, good enough. At that point, the project vision may only be 50% reached. At that point in the project's life cycle, it seems there would naturally be a growing resistance to change by those who have grown comfortable with it. At that point, there's going to be some push back from both sides. If there's a name for this phenomena, I haven't heard it. But, it seems to be the natural order of things.
So, the battle ensues. Should Shuttleworth continue innovating? Should end users complain when he makes the next leap forward? I think both are a foregone conclusion.
If I had to guess, Shuttleworth is not going to be happy until he makes Apple look foolish.
I think Shuttleworth is executing his vision just fine.