Rank speculation: A lot of people have traumatic experiences associated with math, because math is frequently taught in elementary school (computer science rarely is). In particular, math teachers at that level are usually poorly trained (due to the structural disincentives for people with math education to enter K-12 teaching) and/or lack enthusiasm for the subject.
Moreover, at that time in a person's schooling, it's common for a student to be shamed (publicly or privately) and told they're "not good at math". Because socially, math isn't considered a necessary skill (unlike reading), it's easy for a student to deal with this kind of treatment through avoidance rather than mastery. This is completely understandable for a child who has never been told why math is worth doing and has only been taught that it's a tool that will be used to humiliate them and demonstrate their inadequacy, by the way.
So when many adults -- even adults who have enough analytical reasoning ability to be programmers -- hear the word "math", they think back to those experiences, to the time when they were told "you're no good at this", and they freeze up, or else feel the need to prove why math is some useless ivory-tower theory garbage, because of their own feelings of insecurity to do with the disservice that their school system did them.
This is rank speculation because I didn't go to school until college, but I did tutor high school dropouts for a brief period of time, and over and over I'd run into a student who kept saying "I'm not good at math" even though I was there to help them be better at it.