I wholeheartedly reject the notion that a person of school age is inherently unable to determine when his time is being wasted. Frankly, I think your argument is a crass generalization.

For starters, it's ridiculous to think that a person supposedly capable of learning what is taught by the system is incapable of learning how to accurately identify inefficiencies and failures in the system. This ought to be an acknowledged fact in any system that claims to respect it's students or has any faith in their ability to succeed.

Furthermore, it would be downright ignorant to suggest that these inefficiencies didn't exist. They are widely acknowledged as existing in the quality of the curriculum, the teaching, the educational environment, the materials, and in the bureaucracy which surrounds it all. Schools have problems. It's absurd to think that the very people for whose benefit this is all said to exist should simply grin and bear them. In fact, I can't think of a more dangerous attitude to instill in the workers and voters of the next generation than "deal with it". Likewise, giving them the idea that learning is supposed to involve large amounts of pain and hardship is absolutely counterproductive to the goal of education.

Learning is not a hardship. It can be a challenge, sometimes a very large one, but by and large it is an autotelic activity that people are born quite enamored of, and I believe depicting it as an unfortunate fact of life for the sake of making people tolerate their own suffering is "short-sighted nonsense" that most often puts people off of the whole activity. That students find their schooling a hardship worth avoiding ("Math is hard, let's go shopping!") has considerably less to do with the nature of the subject itself or immaturity on the part of the student than it does the excision of most of what is pleasant and motivating about learning in favor of imposing artificial constraints and quantifiable metrics of dubious meaning.

That it is entirely possible to graduate from school as an oaf and ignoramus is indicative of a problem, and for those that both detect that and are not motivated by the extrinsic rewards on offer, it renders the value of obtaining those rewards dubious. In short, if you care about learning more than you care about graduating, modern public high school may not be a good place for you. It may even be harmful.

It's not uncommon for highly intelligent students with passionate interests and a willingness to expend great effort in pursuit of those interests to have an inordinately difficult time with the work they're assigned, being unmoved by the extremely abstract and distant goal of graduation or the threat of punishment so often delivered to underachievers. Those that "deal with it" may wind up with poor or highly inconsistent academic records, which further erodes what value the experience might have had toward achieving their goals by constraining their options for higher education. I think it's a terrible shame that we tell these students that they are wasting their talents, while simultaneously requiring that the majority of their time and attention during the years of their lives where they are most capable of developing those talents be devoted to a system which is at best inefficient and at worst actively damaging.

Make no mistake--I would agree that given the circumstances of inexperience, lack of leverage, and an education system that is at times ferociously resistant to dissent, it can be extremely difficult for a person in that position to make such a large decision with a high degree of confidence, and that errors in judgement are not rare. But I also think that anyone attempting to make it through life without risking such errors is best advised to kill themselves post-haste.

Deciding to drop out is not a decision that should be made lightly or without a sufficiently better alternative readily available, but to dismiss the option entirely on the grounds that suffering is inevitable is foolish and arbitrary.