I agree with the gist of the criticisms here, but from a different perspective. College admission isn’t all about GPA and test scores (whatever the curriculum that was followed).
It’s also about the persona of the applicant: her proven talents (academic and otherwise, e.g., music, art, athletics), her extracurricular achievements – what she does outside of class, what she does in summers, has she won non-school-based awards or recognition, has she led or created things. Loading up on courses at the expense of developing a more general persona is a risky strategy for admission to the most selective colleges.