My mom is perfectly fine using Ubuntu on my old x61 for email, browsing, and YouTube. To be fair she could probably replace it with a tablet if it weren't for the fact that she visits a lot of flash sites (Chinese TV streaming sites).
Likewise my dad is on another Ubuntu machine at home. His work needs access to some software / printers that can't be run via Wine so he's stuck with Windows there.
I tried to convert my 25 year old brother as well, but he switched back to Windows after a month. Despite being the youngest, he hated learning a new system and preferred Windows.