It doesn't really teach CS or anything, but I'd say it does teach "how to think about programming like a computer scientist". Few entry-level "practical programming" textbooks are going to address - even at a cursory level - formal languages, recursion, mutability and immutability, issues surrounding aliasing, HtDP-esque design recipes, composition, and so on.

Even if it's not the best (to paraphrase Churchill: let the clever ones have SICP as an honour and HtDP as a treat), it's probably how I'd introduce the "average" student to CS.