The art of comments never taught properly
Comprehensibility should be one of the foundations of software engineering but I've lost count of the otherwise brilliant engineers who have crossed my paths who either can't or won't comment their code properly.
It's a bit like testing in that regard. Some see it as something to do later if at all, yet there can be few of us that haven't suffered the consequences.
It is odd. I wonder if other engineering careers are similarly dysfunctional!