I'll nitpick a bit.
You can't tell your user to "echo 'awesomecopter' | sudo tee /etc/hostname" if you may have windows users.
And even for purely linux user, "Good: Give the reader a bash snippet that evaluates conditional logic for them" is quite a scary wall of code for a beginner that as no idea why copy/paste that.
All in all, don't confuse "giving the shortest path to a working solution" and "teaching", which both can be in a tutorial, but they have different goals and you should choose accordingly.
I think the "Teach one thing" is probably the best advice in the article, and too often ignored. I remember as a kid reading Swinnen's book to learn Python and having to understand OOP with his example using ions was a terrible experience.
And if you think "well you should have known that, they teach it in school", you are missing the point.
That being said, writing an excellent tutorial takes a lot of work. Way more than a good-enough one. Choose wisely.