If people just would admit that the Americans were overconfident and too placid to take the necessary action on their lovely sundaymorning in paradise, all the "mysteries" would be explained.
People involved just didn't want to see what was coming. They didn't want te hear the possibly bad news. So everything that did occur was explained away, like the approaching Japanese airplanes spotted by radar, just thad to be the flight of B17's. And so on. What did help was the moment of attack which the Japanese picked: on sundaymorning a lot of the higher officers were hard to find so the chain of command was severed and important decisions were taken much later then they have should.
Appearently it is hard just to admit that errors were made. It seems easier, or perhaps protecting the responsable ones (oops antother consoiracy !), to invent a story about a conspiracy.
The nazi's did it about "the betrayal" by the politicians of the military in WW1 and recently we had a "good one" about the 9/11 attacks.
People should bear their responsabilities instead of shove them away and invent stupid stories !
My view anyway.