Interesting point... I recently helped an elderly man (who has very poor reading skills and has never used a computer without help) - buy, set-up, and use his first computer. What did I choose for him?
A cheap Android tablet with a keyboard case. The idea behind this decision was that most people (in a low-income area) that he'd ask for help would already know how to work an Android tablet because they probably have a phone or tablet already. If not, he knows the basics, and it's much more simple than a PC but almost fully-capable with his needs (Facebook, PayPal, YouTube). I also locked it down so that he could get help with his financial data without giving anybody the actual password to his bank accounts (as he was doing before).