The general public is not going to know what a "text stream" is, what a "host" computer is, or what you mean by getting into a computer "manually". And I'd be willing to bet that "interprets" in this context is also going to be difficult. Explaining these things to people who don't care about computers isn't as easy as you make out.
In fact, I expect that the first four minutes would be spent defining most of the words in that paragraph.
And thats assuming you have someone who "clicks" on it the first time around. If they don't, it's going to take a while. Part of the problem is that as you put it, most people don't care. And it's just too costly (in all senses of the word) to really educate people about "computer stuff". This is why we've been advocating user education for years and it hasn't worked.
So we say that we can't teach users not to shoot themselves in the foot. Cool. What are our other options? We can try to make it impossible for users to shoot themselves in the foot. But what we've found is that users ignore warnings. If you make the security restrictions too strict, users can't figure out how to evade them and deem the machine broken. If you make them too easy to circumvent, users go ahead and shoot themselves anyway. If you use a trusted computing architecture, user freedom is lost in such a way that it'd be better for people to be shooting themselves.
If you can't stop people from losing a limb, and you can't tell them how not to do so, what is the world to do?
EDIT: The only thing I can think of is to make computer education cheaper. And I don't mean in the monetary sense, I mean the mental sense. We need to find some way to get more people to care about computers, or make the concepts easier to teach, or make the materials easier to access, or make humans smarter, or something.
This is a problem I spend mental computer time on daily trying to solve. No answers present themselves. I would actually love for someone to show me the silver bullet, or even a box of lead ones. (LINK: http://bhorowitz.com/2011/10/26/lead-bullets/)
EDIT_2: And just for clarification, I'm focusing on all aspects of computing here, not just security or usability or what have you.
