Why MIT switched from Scheme to Python (2009)

The move away from Scheme has always saddened me. The first thing we learned in 6.001 was abstraction and invariance. These are still the core of writing good software. I still use these principles every day. There is a purity to Scheme. It is a beautiful light-weight language anyone can learn over a weekend. It does nothing magical for you which means you get to / have to build everything you want and you must understand how it fits together.

I agree. I was taught Scheme and I later taught it. It was a much cleaner and suitable language for teaching computer science than Python. Students could completely understand the language and how it worked by the end of a semester.

Scheme is much closer to mathematics, which made it much more suitable for teaching strong mathematicians arriving without coding experience. It also made the hackers more rigorous and broadened their minds from the imperative "do this then that" mindset.

There's a notable difference between those first taught scheme and those first taught Python. Of course, both can go on to learning Python or FP or whatever. But that foundation needs to be there to teach truly great coding for most mortals.