There is a sense in which there's justified fear of "trying things" on a computer. While it's fairly hard to permanently break one, it's fairly easy to lose the document you've been writing for the past hour. I remember this being a major issue for my mom back in the early 1980s.
It's not all that difficult to screw things up enough to require a reformat, either, or at least to make a reformat the easiest solution. I think of myself as pretty tech-savvy, and I've had to reinstall Windows before because I somehow borked my registry.
Your example disproves your point. Most people don't even know what a registry is. In general, people don't realize what you can do with a computer aside from the basics, which is what keeps them (relatively) safe.
