Humans with the ability to explain something in a structured way are rare because it requires a lot of different skills. First you need to know the topic well. Second you need to have emotional intelligence to know to current level of your trainee, to get him/her onboard with the new knowledge. Third you have to think about how to group and link the information you want to communicate. Forth the content must be reduced to the bare minimum and then plan what else should be explored, since learning with a tutor is most times the beginning of a voyage and not the end. This is hard, so people fail at it all the time.

The default – a.k.a fallback method – is to just list all things. This is not only confusing as hell, it is even worse. You never know what you don't know with this methodology, because you have absolutely no context about how something is meant to be use...

For example Books about programming languages often explain only the rules of the language, but totally forgets to explain how the language is used in practice and which tools are commonly used or which homepages have useful content that almost every programmer of language X uses. A greenhorn has understandably a very hard time without all those information.

E.g. setting up a Common Lisp project with Quicklisp which has the code under a namespace takes 20-30 steps (installing Quicklisp using a Lisp REPL, configuring Emacs, configuring the project) – no wonder almost everyone gets lost in the process. And a lot of programming languages are like that.