now if Canonical/Ubuntu Community was helping to turn users into contributors at a slower rate we'd have a problem that the linux community should reflect on
I disagree with you
if Ubuntu is introducing twice as many people to linux and is converting half as many to contributers they are still just as good as other distros.
or if they are introducing people to linux who would never use the other distros, but only converting 1% of those people into contributers, it's still a net win for the number of contributers
this is completely ignoring other effects of "non-contributing" users
testing (even those users who don't run 'test versions' find and report bugs)
teaching other users
calling for open standards
voting with their wallet (or their companies wallet) for hardware that supports opensource
paying opensource companies/developers
not to mention reducing the amount of money going to microsoft and other proprietary-only vendors.
do you think that there is any chance at all that Adobe would have released a 64 bit flash for linux if the only people who used linux were people that contributed directly to opensource projects?
in other words, users do matter, even if they aren't "contributers".