Programmers often discover solutions while explaining a problem to someone else, even to people with no programming knowledge. Describing the code, and comparing to what it actually does, exposes inconsistencies. Explaining a subject also forces the programmer to look at it from new perspectives and can provide a deeper understanding.
I don’t think they care as much for minimizing trauma as they care for cheap labor from a developing country. I doubt there are a lot of 4chan users there.