Reliable and transparent programs are usually not in the interest of the designer.
Software development is technical activity conducted by human beings.
Software gets slower faster than hardware gets faster.
But quality of work can be expected only through personal satisfaction, dedication and enjoyment. In our profession, precision and perfection are not a dispensable luxury, but a simple necessity.
I have never designed a language for its own sake.
Experience shows that the success of a programming course critically depends on the choice of these examples.