It relates to our typically low tolerance for uncertainty. People would really rather suffer horribly with the devil they know, because the very idea of change fills them with such profound reflexive dread.
This is a useful datum for me to know in my ongoing inquiry into the intellectually indefensible aspects of medical science, as they affect my care. It's a ray of light.
Why? Because, on the one hand, I grew up with a higher than average level of variety in life, so it's not that scary to me; and on the other, my baseline state involves rather a lot of nausea, toxicity and pain, so the devil I know has serious competition. This reflexive gag-response to "thinking outside the box" has never made sense to me.
It has been clear to me for ages that people would rather suffer horribly and endlessly in their lives, rather than endure the mental discomfort of change. I'd like to know how to circumvent that, short of putting them through the same experiences as me. If those data surface, I'll be happy to share them.