There is no conspiracy theory in Pearl Harbor. Harry Truman made the infamous statement "the buck stops here" but he didn't really mean it.The fact is that FDR failed to protect Americans even when he knew that war was imminent. Failed administrations often blame subordinates for their own failures and if the media cooperates they usually get away with it.
If only FDR had gone to Pearl he could have advised the navy on how to protect their ships and base, but no, FDR sat in Washington expecting the navy to fend for itself.