That is why I said:-
by and large they are written by people who do not know what they are doing.
There is so much bad stuff the blanket advice must be to avoid the site at all costs. After you have been here a bit you will see how much crap we have to try and mop up from that site. The problem with it and the similar hackster.io is that there is absolutely no quality control. Anyone can put up anything.
I know, that's definitely a problem, and I totally agree with you on that.
I think that part of the problem is that the really good documentation is too much and too complicated for beginners, so new users will go read articles that they can understand, and that are more practical, like on Instructables.
But a lot of these Instructables are grossly oversimplified, or encourage bad practices, like omitting LED resistors, driving motor's directly from the I/O pins, no flyback diodes ... all that kind of things. If you don't know what the actual purpose of something is, it's easy to just forget it, or simply ignore it.
But on the other hand, if you write an article explaining why you should use all those extra components, it'll be quite hard to digest for many new users.
Also, the documents at https://www.arduino.cc/en/Tutorial/ often don't make it on the first page of a Google search. I think it would help if they were easier to find, for example links to those pages in the built-in examples (not just a url in the comments that you have to copy and paste), a message when you first open the software.
Even on the Getting started page, there's no real help for new users. I mean, when you're new to Arduino, you don't care about libraries, cores, or an introduction, you want to know how you can write code, and make it do something.
I remember myself 'getting started' with Arduino, I opened up the IDE, and it was like Chinese to me: I didn't know anything, didn't know what a compiler was, didn't know what a COM port was ...
It would be nice to see an official page explaining those basics, and point you to some specific examples to get started, like blink. There should ideally be some structure, just a list of separate examples is not very handy: you don't know what the reader already knows, for example, if you offer the examples in a particular order, you can gradually explain things, you don't have to explain the basics in every example, etc ...
And I know that's exactly what those books do, but they can be pricey, I didn't really want to spend €20-€30 on a book without knowing if it was any good, and there were just too many choices. One or two recommendations on the Getting started page would be much easier for beginners.
Anyway, that was enough complaining for an entire week, I'm sorry ;) .