This is a quantified reduction in ability, not a subjective gripe and one that is very commonly observed. A lot of programs are admitting under prepared students.
How effectively is it controlling for factors?
> A lot of programs are admitting under prepared students.
Sure. But there remains the question of _what_ should the students be prepared for, and are educational institutions providing that substance? Meaning, are students under prepared because they don't know how to succeed in a college environment, or are students under prepared because colleges don't know how to teach in a modern environment?