I don't mind arrogance on public personas[^] who are very good at what they do. Think Steve Jobs arrogance. Think José Mourinho "I'm the special one" in 2004. I read it as putting your (reputational) neck on the line. "I'm so sure of this assertion that I'm risking my reputation here.". Taleb is one such brilliant mind.

The downside to arrogance is that it will tank your reputation if you fail. This may be too early in History, and too politically charged to use as an example, but think Trump.

[^] on personal interactions, though, I find arrogance a repellent trait.