If I remember right, that post wasn't designed to highlight a practical use-case, but rather to set up a simple task as a "how could I apply this?" type of experimentation. The guy got roasted for it, but I think it's a very reasonable thing to try because it's a simple task you can see the direct result of in practice.

The cost problem was highlighted as well, because if such a simple task is a problem, it can't possibly scale well.