Yeah, the high-capability outliers are used to coast in any subject and may or may not have time to adapt to the laborious requirements before failing.

Also, anybody with "street-smarts" can see the cost-benefit ratio and perceive the benefit is kept much smaller than some other, easier subjects, while the cost is artificially inflated.

What it does select is people that really love the subject. And is at least a little bit smarter than average.