At least from my point of view (in the industry, not academia) this is actually the opposite. Math graduates tend to be smart and humble and I respect them a lot. Sometimes it almost feels like math and physics are the last "real" degrees left.
I'm talking about professors at R1 schools and Ivies to be clear.
Yes, and those are the ones who didn’t make it to researcher.
Similar - I found math majors to be fairly humble. Yes, there's always the exception, but I found them to be fairly fun folks.
Physics majors, in my experience, had a significantly higher arrogance level.