If you are talking about general public distribution, out-of-the-box
usability for the computer illiterate is probably a must. I'm linux neophyte
and want to use Trisquel for ideological reasons, but also because for the
most part it is a great, easy to use distro. That said, I have struggled at
times, and if I hadn't had the time to educate myself even a little, or had
some great support here at the forums, I would have been likely to not use
Trisquel. And example is the graphical updater, which doesn't work
apparently. That is bad. In no way could I have been able to investigate
alternatives and learn the Terminal commands to install updates on my own.
Luckily I had the time and inclination to get help. This is just my
experience of course. Maybe the new generations will have a basic knowledge
of key and terminal commands. But I'm not so sure.
Hope that helps.
Love Trisquel and want it to grow.