No doubt many of us would reason the way you do - but do you know any court that would tolerate that? Then why would we find it acceptable behaviour in someone aspiring to be on the highest court of the land? During the hearing, Kavanaugh acted essentially like a politician in a campaign debate: evasive answers if they weren't outright lies, counter-attacking, pivoting from difficult questions to boasts about oneself that don't answer the question, accusing the other party of conspiracies. That may make him a suitable choice for a position in the Trump administration, but it certainly makes him unsuitable for the SC.
And I still really don't get why he did that, because it seems so blatantly stupid, whether from the perspective of his reputation as a future SC justice, if confirmed, or from the short-term tactical perspective of winning confirmation votes, since he cast a permanent cloud of suspicion over himself while also giving the Democratic centrist senators ample reasons to reject him. The only perspective from which it was not a foolish move, as far as I can see, is if he was more concerned with the midterms than with his own confirmation, meaning that firing up the Republican base was worth it even if it reduced his chances. And even then it seems like a gamble.