In your example, you need to fix a specific broken mechanical part, which takes time and resources to fix if it was designed to be fixed at all by a home user. In my example, the information is freely available, costs nothing to duplicate or implement, and is simply a small investment of time--which will pay huge dividends if made.

Most computers even come with all the tools needed to fix them, something which cannot be said for cars. It just takes patience.

It's a lack of critical thinking and problem solving ability, that's all.

Exactly these abilities that most people do not have. And those who do are usually called "engineers", "programmers", "doctors" etc.