My understanding is the same and I believe it's pretty obvious why they always seem to be that way. It takes a tremendous amount of self-confidence to push through "the system" in any meaningful way and that often comes off as assholish. It also causes them to behave the same in every aspect of their life. They don't compartmentalize being an asshole in business, but they're a Mr. Rogers for everything else.

That kind of confidence is pervasive in every aspect of their being. They don't have room for doubt.

Reading about wartime generals solidified the thought in me. Many generals like Patton weren't even very gifted strategically, but they were confident and authoritative in their decisions. Oftentimes, that's enough to pull off a victory.