I think the controversy is that, when I read this, I get the impression that GNOME devs either don't believe that backwards compatibility is possible in the long run, or that it's at least unpractical. I don't really get that impression given QT's backwards compatibility, MFC, etc, but if they really believe it, then faking it is unproductive, and just making a more distro-like release plan is reasonable.
I really can't get the distro comparison out of my head - it's like they tried a single release that lasted forever, and that didn't work, so they tried a rolling release, and that didn't work, so now they're going with unstable releases with LTS releases every 2 years.