People who have the opportunity to attend an elite university and decline it would be doing so because their opportunity cost is better.
But the question is still open: why should credentials not be open to fair competition? Shouldn't a poor woman in Africa be able to compete for the same computer science credentials, bar exams, medical exams (this would require further vetting of practical lab skills) as a Harvard student, through the same exams and projects? Of course, Harvard could still give its students its own stamp of approval, but the education and credentials should be open to competition, not behind walled gardens.
People who have the opportunity to attend an elite university and decline it would be doing so because their opportunity cost is better.
But the question is still open: why should credentials not be open to fair competition? Shouldn't a poor woman in Africa be able to compete for the same computer science credentials, bar exams, medical exams (this would require further vetting of practical lab skills) as a Harvard student, through the same exams and projects? Of course, Harvard could still give its students its own stamp of approval, but the education and credentials should be open to competition, not behind walled gardens.