But it would be good for the future of their relationship if T'Hesh knew her place. An outburst like that out in the public might jeopardize the ship or at least the discipline aboard, an issue Spock should be concerned with - perhaps even over winning the argument at hand.
It's not merely due to the prevalence of certain personality types that people in leading positions tend to be assholes. It's actually a survival trait and a desirable feature in them - especially in strictly hierarchial organization. Approval just plain isn't required, just obedience.