SICP claims "programs must be written for people to read, and only incidentally for machines to execute". If that's true, then a language's suitability for exp

SICP claims "programs must be written for people to read, and only incidentally for machines to execute". If that's true, then a language's suitability for explanatory/conceptual purposes is its primary virtue. The right question to ask about a language is, what concepts does it help explain?