I agree with this:
I won't put Ubuntu on anyone's system with full updates enabled, only security updates. It's too much to ask that Linux enthusiasts become the new tech guy/gal for everyone they encourage to use Linux.
Though in time I suppose you could convince people to want to invest more into their OS (not unlike a garden, more work than just going to the grocer but the vegatbles are sooo much better) for the most part people just want a tool that works consistantly with little or no maintenance. I considered putting Linux on my mom's old computer but I'd have to install and update it and check for bugs and make sure it was quite stable before handing it over. Even then I worry that she may update something and I'd be getting calls as to why her computer is "acting funny."