Apartments: unimaginable problem, page-29

The central fallacy in current thinking is that anyone can be anything, given training. ie. we are all equal blank slates.
Just passing an exam, while important in itself, has nothing to do with how much interest, care and work ethic someone has.

I agree with the 80/20 (or 90/10) rule. There are a few people who are truly born into their trades or professions, the rest range from abysmal to very competent.