I’ve been thinking about this and agree it’s a really big problem. Most non programmers search the site for rules, to copy and paste, without really understanding how the code works. This works for the most part but if adjustments are needed for extra functionality then a post for help usually results in a solution and everyone is happy.
So, the question is, how many people are willing to read a book and learn vs posting a problem and receiving a solution? You may be able to answer that question by looking at the number of post, for help with a rule, and the amount of info that is given by the poster. How many times have you seen a reply, to the OP, that ask to provide more info than just the error message? If there wasn’t a description of what to post when creating a new topic you could simply say they didn’t know any better.
Personally, I would love to see you make a tutorial or write a book about OH rules. Maybe start with a good foundation, what is an Object, Function, Class, etc… and how they work together. I’m not a programmer, so this may be similar to someone trying to do calculus or trig without learning algebra first. In this case your book may require a few volumes. 
On the other hand, if you do just enough, how often would you have to revise your tutorial. I’ve read several post about OH updates and rules not working afterwards. The solution often involves something to do with how the rule was coded. This also brings up the question, how many version of OH would a just enough tutorial cover?
I’ll stop my rambling here because I suspect you’ve already thought thru everything above, plus some.
My opinion would be to write the tutorial/book, start with a good foundation and understanding, that allows us to adapt to future changes and possibly even community contributions.