You're right. A lot of users simply can't be trusted to make good decisions.

There has to be a way to protect those users without shutting down power users, though. I don't know what it is, but Apple's approach of giving power users a big middle finger is not good.

Apple isn't alone in this, Microsoft and Google are also heading in the same direction.

At least there were 9 who "did the right thing" - 21% - which to me suggests that not all users are idiots and a fair number of them are knowledgeable. It would be interesting to do this study again, nearly 7 years later, and compare the results.

The real danger of assuming that users are stupid is that it means they'll likely stay stupid, as then even fewer will learn due to the lack of any motivation to. My cynical opinion of why this happens is that for these companies, it's actually advantageous to keep users stupid; you can extract more profit from them if they're kept happy, unquestioningly complacent, and consuming. To paraphrase an old analogy: if you keep someone from learning how to fish, you can keep selling them fish.