I kinda see what you mean in that Mao is confrontational and that one of his innovations in dialectics is an emphasis on destruction in the resolution of contradictions (rather than just thinking of sublation almost as a form of incorporation, or perhaps of synthesis as primary/only way for dialectical contradictions to resolve).
But there are a lot of ways to defeat (or even ‘crush’) a collective enemy, including in violent conflict, far short of extermination! I don’t think Mao’s ideological combativeness or record as a military leader should (or can, really) be mistaken for the kind of raw bloodlust we can recognize in a call to ‘exterminate’.