I’m having flashbacks... Thanks for that ;)

Time complexity was my worst CS topic. At least, for implementing the most efficient system. I’m not an algorithms guy.

Correct me if I'm wrong - I just went to an unrespected state school - but I would think that the MIT admissions filter selects for students who wouldn't particularly struggle with something as small as language idiosyncracies, especially in an introductory course.

I digressed a little. Point being: while I'm unsurprised that some % of people from a broader range of abilities couldn't get functions or iteration or inheritance or whathaveyou to stick, I'd be very surprised if ANY % of the culled-by-18 right end of the Bell curve couldn't grok both fundamental concepts and any relevant part of the standard documentation (on which we appear to be in agreement.)

As someone who has been part of running intro courses using a variety of languages: While I like the Scheme path for various reasons, I do not recognize the effect you imagine at all from the students I've seen. That there are complex areas of Python is basically irrelevant for intro courses, the few pain points are really easy to explain and remember, and Python is great for the experimentation phase (the core is easy enough, the (standard) library ecosystem helps satisfying random interests and can generally also be used without being exposed to problematic parts of the language, REPL)

By this measure C should be a popular university intro language too, but it is famously unsuitable as a first language, at least according to academics.