Production-quality fonts usually have huge amounts of tweaks and fine-tuning to make them look good. Characters won’t be exactly the same height, they’ll be a bit above or below their nominal position, that sort of thing. Those tweaks also make those fonts completely useless as reference for developers.

What this font gives you is a bunch of boxes and lines with well-defined, predictable sizes and positions, which makes it very easy to validate that your text rendering/layout is at least somewhat sane.