[heavyset_go]

> As it is, this entails limiting the users' freedom to tinker in such a way that they simply cannot screw things up no matter how hard they try.

I've had my parents on Ubuntu Linux for a while now for exactly this reason: no matter what they do, they aren't going to screw things up, even if they tried. It just works.

So far there have been no complaints and no issues.

[fogihujy]

Ditto with my in-laws and Linux Mint. Thing is, they don't really care about tinkering (just like most people) and so they don't care. Allowing them to tinker would benefit them very little, while it would definitely increase the risk of them screwing things up.