AKuperma, it seems like Orthodox Jews like to believe that secular education is a monolithic exercise, in which there is one school with metal detectors at the door, pervasive immorality, social promotion, skyrocketing failure rates, and overwhelming malaise. But there’s not just one goy who’s getting one education. High-level academic performance at good schools develops specific skills as well as specific knowledge, and the people who would like to see more secular education aren’t arguing in favor of terrible secular education but in favor of good secular education. But even if the cost of going all out doesn’t justify the return, it doesn’t follow that the frum world should expend no effort at all on secular education.
Besides, you’re extrapolating from a few individuals who are by definition gifted, to reflect on everyone. Possibly the person who will go on to be history’s greatest economist had an affinity for economics so strong that he could have taught it to himself; although arguably there were fifty other potential greatest economists who were never introduced to economics, spent four years in kollel, and ended up working in a grocery. Either way, the average person stands to gain from education, both as a general matter and as a method of earning a livelihood/developing interests/succeeding at life.