You may be amused, but in Europe the technical details of a car engine, transmission, breaks, etc, and how to perform a quick repair have been part of the drivers test (and was still, when I made mine). It was a three parts test, involving a technical part, a legal part, regarding rules and laws regulating traffic, and, finally, a practical test. (Similarly, understanding how analog radio works was part of high school curriculum.) This was based on the conviction that dealing with a technology also afforded a basic understanding of it, not the least for legal/liability reasons.

Analogously, just making that red "No SSL" alert "go away" may be not enough. It may be preferable, if users were to understand what this is and why it is important, what the possibles consequences are, etc, if they would be actively looking for this, if they would and could confirm the mode of their interaction. Not the least for legal/liability reasons. (Teach them first to never engage in any critical interaction unless there's a verified, secure connection as indicated by such and such icon or signal. Facilitate them in asserting this. Then put on an additional warning light, but don't replace the former by the latter. There's no "easy mode", no "My First Sony" – which was, by today's standards overly complex, anyway –, when it comes to your livelihood.)

A critical mass of people able to make informed technical decisions — which is what both business & democratic self-government require.

> We don't expect people to understand the details of how their car engine works, or how digital radio signals are encoded and decoded, why should we make it necessary that they do so for the internet?

We don't expect them to know the deep details of those technologies, but we do expect them to know that flammable gasoline powers an engine; we do expect them to know that radio signals can be received by anyone with a receiver (and a key, if encrypted).