Second, your security clearance is not supposed to be useful to you; it’s supposed to be useful to the government. If you are attacking the administration every day—if you are literally calling the president a traitor, as Brennan has—there is very little chance that you will be consulted. Officials will keep clear of you, so you’ve destroyed the utility of giving you a security clearance.
I would add a third consideration. I cannot recall previous high intelligence officials acting the way Brennan and Clapper have in vocally assaulting the succeeding administration in a highly partisan manner. Think of Directors of National Intelligence John Negroponte, John McConnell and Dennis Blair, and think of CIA Directors like William Webster, Robert Gates, James Woolsey, John Deutch and George Tenet, and you’ll immediately see that what’s happening now is unprecedented. Brennan and Clapper may well believe that Trump is a threat to the country and as such, merits a break from the norms. They are entitled to their beliefs and can go on attacking—but they shouldn’t have access to classified information.