Well it's not really due to cononical or anybody like that.
What it seems to me is that they have been able to garner a following among neophite Linux users that not only want to test and run bleeding edge software, they want to get all their graphic goodness to go with it.
Since graphics in Linux sucked for so long the only effective vendor for people wanting superior 3d performance is Nvidia. It's not the user's fault that this has simply been a fact of life for Linux for a long time now.
Nvidia makes unstable drivers. For Vista or XP or Linux they are going to be a major source of issues; it doesn't matter. With bleeding edge versions of Linux that are unstable to begin with then your going to run into a lot of crashes.
So it's nobody's fault really.. not anybody here or involved with Ubuntu. This is why we have beta testers and they are doing their jobs. Everybody should be thankful that this problem is being resolved now rather then on your servers and workstations.