"It's a defense mechanism for sure - but not for that reason. The real reason, in my view, is that techies are terrible at recognizing intelligence/skill if it does not somehow relate to math, logic, or, more concretely, code. I have no idea why, but the shoe fits."
I really don't agree. I have/had nothing against business people (they always threw way better parties in college after all ;).
Similarly, MBAs are great at running businesses. The trouble arises when we do what we did in the 90s and let them drive the businesses, make the businesses, that sort of thing.
The issue can be summed up I think as MBAs squeezing out high status technologists (http://www.codebelay.com/blog/2011/08/14/low-status-and-high...). When that happens, the 90s happen. To fight this perceived threat, we have negative stereotypes that keep people on their toes. They are essentially antibody memes.