The point of this post is education. The author is trying to de-mystify garbage collectors. His approach - which I think is a good one - is to present code that

The point of this post is education. The author is trying to de-mystify garbage collectors. His approach - which I think is a good one - is to present code that is quite simple, but still meets the criteria for being a garbage collector. This is a pedagogical technique. Your points are valid, but they also ignore that the author is trying to teach concepts through code. That often require simplification.