[oftenwrong]

Most code maintenance issues don't really appear until a relatively large amount of code and code evolution is involved. It's hard to include that in a blog post while keeping it digestible for the average reader.

In a small example, excessive duplication is not a problem, and excessive DRYness is not a problem.

Therefore, it makes some sense to me to leave out code, and just hope the reader has personal experience to draw relevant examples from.