I think the performant rudeness is part his way of keeping the herd in line. A big display once in a while can take less energy and be more effective than continual small corrections. Consider the actions of the lead bull in a herd of elk. Consider that Linux has been developed by a group of men using male ways of interaction, which have remained unchanged since Homer.

Think back to the arguments between Torvalds and Tannenbaum. Linus earned his place through a combination of technical prowess and forceful personality.

Consider that Linus can now afford to transition to the role of the wise elder. That role traditionally adopts a more considered and politic view when resolving conflict.