Who screwed up worst should have been left to the historians, which means when the war is over.
The problem is, too many politicians wanted desperately to hang it on George W. Bush — just like too many politicians wanted desperately to hang Pearl Harbor on FDR.
The surprise is not really that a commission was convened. The surprise is that only one commission was convened. For Pearl Harbor there were at least four that I can think of off the top of my head; and the WordIQ Dictionary via indispensible Google reminds me that there were nine:
The US government had nine official enquiries into the attack the inquiry by Secretary of the Navy Knox (1941), the Roberts Commission (194142), the Hart Inquiry (1944), the Army Pearl Harbor Board (1944), the Naval Court of Inquiry (1944), the Hewitt investigation, the Clarke investigation, the Congressional Inquiry (194546) and the top-secret inquiry by Secretary Stimson authorized by Congress and carried out by Henry Clausen (the Clausen Inquiry (1945)).
And look at the dates. Every damn one of them conducted at least in part while the war was still raging.