I've never understood the idea of a 'teaching' programming language. (Modulo examples like Logo and Scratch, which offer much more than a language as part of a wider teaching/computing system.) You spend all this time ramping up on a language, toolchain, library, etc, that you will eventually be unable to leverage beyond a certain point since it is not one used by everyday programmers. The delta in "quality learning"…
The idea is that the concepts of CS are universal, regardless of programming language. So instead of using a programming language that has been designed for real world use (carved with the footprints of a thousand language hackers, full of awkward inconsistencies, warts, and good-enough-for-nows), teach in a teaching language - a programming language that is very regular, with very simple semantics, not necessarily d…
Everything you mention here is a consequence of age not intent for real use.
An old teaching language would be just as bad if those are your only criteria.