I think, being a BSD user, we're probably not concerned much about that. Gnome 3 accounts for a miniscule proportion of users. It's less relevant that Gnome 3 doesn't work on BSD to the BSD projects than Gnome if you ask me.
Bad PR for Gnome would cost more than bar PR for BSD.
Anyone is free to help out and ensure that GNOME runs on BSD. But if nobody spends any effort, then don't complain when it goes wrong.
At the moment even the feedback is pretty bad. There is 6+ months of development all done in the open, to only hear much later that some decision made 9+ months ago had a unforseen side-effect.
Bad PR for Gnome would cost more than bar PR for BSD.