To be fair, when you actually look at Structure and Interpretation of Classical Mechanics (which is a great book), it's still math that a physicist recognizes,

To be fair, when you actually look at Structure and Interpretation of Classical Mechanics (which is a great book), it's still math that a physicist recognizes, not so much an ALGOL-esque program. The Scheme system was extended to handle the math rather than the math brought to the language. What they did was make all the math explicit, mostly by inserting all the necessary pieces of differential geometry that were glossed over in all other treatments.