By that argument, any blog post that does not contain a comprehensive software development education can be criticized.
You should ask whether these techniques are useful in writing correct code and if they save developer effort, rather than picking apart irrelevant aspects of the toy example.
I don't think modern graphics code represents individual pixels as strings either, would you dismiss the post for that reason?
When to use such techniques, and whether they make sense in the real world, performance wise, should have been part of the "whole point" all along.