Not surprisingly perhaps there have been considerable introspection among former and current officials who have worked in those and related government positions, many of whom would agree that there is urgent need for a considerable restructuring and reining in of the 17 government agencies that have some intelligence or law enforcement function. Most would also agree that much of the real damage that has been done has been the result of the unending global war on terror launched by George W. Bush and Dick Cheney, which has showered the agencies with resources and money while also politicizing their leadership and freeing them from restraints on their behavior.
If the tens of billions of dollars lavished on the intelligence community together with a "gloves off" approach towards oversight that allowed them to run wild had produced good results, it might be possible to argue that it was all worth it. But the fact is that intelligence gathering has always been a bad investment even if it is demonstrably worse at the present. One might argue that the CIA's notorious Soviet Estimate prolonged the Cold War and that the failure to connect dots and pay attention to what junior officers were observing allowed 9/11 to happen. And then there was the empowerment of al-Qaeda during the Soviet-Afghan war followed by failure to penetrate the group once it began to carry out operations.