Good question. I think a lot of it is that many people get comfortable with their knowledge/experience level and they aren't willing to go further. And that's fine, I guess, expect when that unwillingness becomes hostility toward those who are more adept on a particular subject. That's where the tribalism comes in, I suppose.
I've always been curious about learning things that are outside of my knowledge area. And it could be on any subject. A few years ago my wife and I went back to her old stomping ground in Binghamton, NY to visit old friends. While my wife and her friend were discussing how things had changed over the years at the hospital, I spoke for hours with the lady's husband. He runs his own business as a taxidermist. I thought his experience of getting into that business and being an entrepreneur was the coolest thing.
Contrast that with a conversation I had after I graduated business school and went to work for an investment bank. This guy's frame of reference was the local branch of a commercial bank. I tried to tell him that being an investment banker is not remotely the same thing as being the drive-up teller at Regions. And I tried to explain to him about the work I did. He didn't believe me. Eh, what can you do? People are going to believe what they want to believe.