Kavanaugh wasn't some schmoe off the street. He is a sitting Federal Judge with a lifetime appointment to the D.C. Circuit -- the most influential court in the country beside the Supreme Court. Unlike Senators who are elected by a single state, Kavanaugh was confirmed to that lifetime appointment by the Senate as a whole. He was entitled to at least as much fairness and respect as were the Senators considering him for the Supreme Court.
He clearly did not get that. They publicly smeared his name to the media, their supporters, etc.., not to mention clear gaming of the process to delay a vote on his confirmation and to let these allegations fester before giving him a chance to rebut them.
He was nicer to them than they deserved.