Greg is above all a kernel contributor. Ubuntu may have won the hearths of many users but Canonical's insistence on directing the entities that do the work while contributing little didn't earn it a lot of goodwill from people like him. After Launchpad's "let us manage your projects for you" Canonical's hubris has reached such ridiculous levels it seriously proposed that other distributions synch their releases with its own (and Greg's numbers show clearly it had precious little to contribute to such a project).
Thus, of course there is a backlash. Canonical is behaving like it had lots of credits to spend, while doing precious little to earn them.
PS. On the exact count subject please remember that all the volunteers loosely affiliated to Fedora or OpenSuse don't contribute to Red Hat's or Novell's numbers either.