Doesn't teach you to do pixel art, which in my opinion is way harder than vector art.
That's...kind of the point of the tutorial, isn't it? Programmers have a tendency to be less talented when it comes to the art side of the equation. More often than not, they NEED a form of art for their games that is easier and faster than hand-drawn pixel art. And let's not forget that vector art is a lot easier to produce using pure code. (which a programmer would find much easier to understand)
You need to play to your strengths. If coding, and not traditional art, is your strength, then it makes sense to use a form of art in your games that can be produced using coding.