Also even if you had the best students, they are constrained by the institutions they are in and the experience of their professors. It takes generations to develop deep institutional experience and culture. They know this, and expend a lot of effort trying to get experienced Chinese academics that have studied abroad in western institutions to come back to China.
And, also, if you know the syntax of a few languages cold, but you have no creative practice at problem-solving, are lacking foundational computer science concepts and practice, then by the time you are in college or grad school, another language may have come along, while you may have to struggle to apply existing knowledge and creativity to new tools (which is the point of a CS degree).
Some students have no mental toolkit to rely on other than brute force memorizing the syntax of a new language. The difference is highly noticeable, even at a low level of college work.