For that matter they tend to be pretty bad at anything even adjacent to experimental design, but god help you if you point out that the data they're so proud to present to the C-suite next week is, actually, meaningless (rare is the C-suite that'll catch it and call them on it, anyway, so from the perspective of the presenter it's almost beside the point; a disturbing amount of "data driven" leadership is pure fairy dust).
For a good proportion of programmers I'd expect education and professional work experience to have them comfortable with wide estimate ranges being typical and honest for many "90%" estimates, but business-social experience having convinced them, correctly, that honest estimates aren't what a hell of a lot of people actually want and do, "make us appear ignorant or incompetent" (from the book), in actual fact from the perspectives of people who control our budgets and wages.