It might well be useful. You'll get challenged a lot less if people fear you and your power. But that doesn't mean it's necessary, or even that it's not counterproductive to greater success. Even in the post, Carmack alludes to a couple battle he lost with Steve where Carmack's view was eventually vindicated.

By the way, you criticize the previous commenter's assertion, but you haven't provided any rationale on why they might be mistaken.