I will betcha that if they went down that road the 4.0 we would get in 6 months would have more unfinished blue sky features and frameworks and would have been less usable than the real 4.1. (again look at E17)
And I won't even talk about the number of ported apps.
Net result: 1 year+ wasted.
Release EARLY release OFTEN.
4.0 did work and was OK to release .. the "mostly erects the pillars of KDE for developers and upcoming releases" part is the only thing that should have been in big letters in every announcement and blog post and Fedora should have been more conservative.