Am I missing something, or does this article basically say: within the domain of self-taught and c-educated programmers, there are groupings with various levels

Am I missing something, or does this article basically say: within the domain of self-taught and c-educated programmers, there are groupings with various levels of theoretical and practical skill? It seems it wouldn't be a stretch to say that, "cs-educated programmers" aren't even really identifiable by trait, since course selections made by both the university department and the student can change the curriculum unpredictably. The same could be said for "self-taught;" in my experience, half the people in cs-related math or theory classes just read the book and don't bother to attend class anyway.