Most art tutorials suck.
This issue has been bugging me for a long time already and I'd like to write why. I will mention canines often, first because they're a good and known example, second because every other tutorial here seems to be about them. I'm also keeping animal tutorials in mind, but this all can apply to many other art tutorials as well.

I find that people often don't understand one thing: tutorials will not magically insert skill into your head (or hand). They're not books and their space is limited so they need to get straight to the point and explain that one thing they were made to explain. You'll already need to know how to draw if you want to make use of them. A tutorial on how to draw dogs will not teach you perspective, foreshortening, colour theory, gesture drawing and many, many other things you need to learn in art. They also can't replace that one magical thing done over and over again for improvement: practice. And I'm not talking about repeating the same thing the tutorial is telling you, I'm talking about going somewhere else and drawing a hundred different dogs before you finally really learn how to draw them. It's not that you shouldn't put what the tutorial is telling you onto the paper, but you shouldn't rely on it as if it's the only source of reference you have. A tutorial is short and limited so keep in mind that what it's teaching you also is.

Another thing I keep noticing is that people apparently can't tell what a tutorial is. A TUTORial is meant to explain and teach you how to do something. A sequence of WIP-s without any explaination isn't a tutorial.
Also, a tutorial on making comics is NOT a tutorial explaining how someone drew a page of their comic. The kind of tutorials I mentioned in latter example is something that spread like a plague across the published art-teaching world. I keep seeing books like these all the time. Books that promise to teach you how to draw, say, dogs and their "lessons" go along these lines: First you draw a circle for the head. Then you draw a circle for the body. You connect them to make a neck. Then add a muzzle, ears and eyes and you're done! . I bet you've seen this a lot. This is not teaching you how to draw dogs, this is teaching you how to draw, and really terribly, might I add.
I'll use a simple analogy from a competely different area to clarify the difference between a good and bad tutorial. Imagine someone is trying to explain to you how to solve an equation, for a test. After they finished expaining, you try solving the same equation again and you solve it correctly. But you get an F on the test, because apparently you can only solve that one equation you were taught to solve. Another teacher comes and actually explains to you how to solve that type of equation and why you solve it the way you do. You go take the test and you get a good grade because you know how and why you have to solve that type of equation in a certain way.
My point is, tutorials that just teach you how to re-trace the same thing are not good tutorials. Tutorials explaining WHY and HOW are.

If you're making a tutorial yourself, first: please, KNOW HOW TO DRAW! If you're not completely comfortable with drawing something and knowledgeble on the subject, don't teach others how to draw it.
Second, if you're trying to teach someone how to draw a dog, please refrain from using your own style. A stylized dog's proportions won't be useful to anyone but a copycat.

I'm not saying all tutorials are doomed or useless, but a good tutorial should be done by someone who actually knows what they're doing and offer explanations rather than just keep stating: "You do what you see in the pictures". And art tutorials are good for getting tips, but that's about it.