Survivorship bias might be an issue here. The professors went through their education and careers without anyone teaching them how to debug, and they survived.

Survivorship bias might be an issue here. The professors went through their education and careers without anyone teaching them how to debug, and they survived. All their colleagues went through the same process, and survived. Maybe they can debug their own work and the work of undergraduates, but they were never taught the process, they just picked it up by osmosis. The article says the professors used the phrase "some students just can’t hack it in engineering" which suggests they see some aspects of engineering as things that can't be acquired, intrinsic abilities of those who can hack it in engineering. If they see debugging (or some related skill) as one of these aspects, then they wouldn't see any benefit from teaching them.