Why single out managers? This is a quality of pretty much all people including arrogant tech workers who think they are better than everyone else.

I was surprised by the number of times I've seen the most-voted comment on HN was outright wrong, or so off the mark it was not even wrong (in subjects at the periphery of tech where I have personal experience). I think managers & tech workers figure "Since I'm really good at X & Y, I must be good (in general). I have figured out how the world works (or can figure it out, after giving it a few minutes thought)". It's hubris.

Take the currently most upvoted top-level comment on this thread for example, about how everything is a "system."

Because rank and file employees don't get to effect change on an entire department or company at a whim the way managers often can.