No, it's not that the Apollo moon landings were fake - everyone knows that.*
My conspiracy theory is that many or most of the space scientists who say they support NASA's manned space exploration are lying through their teeth. I don't think anyone can adeptly play the game of getting NASA money for an unmanned project you're working on, while simultaneously dissing the stupid and politically powerful manned program. I think the scientists are playing politics.
The moon landings did good science, although that wasn't the main reason for them. Since then, the manned program has been a huge disaster, and Obama to his credit has started pushing away at it. I say leave it to private industry.
Meanwhile, not much has surfaced about the mysterious resignation of the NASA's science chief, although it likely had something to do with political infighting over Mars funding. A great comment here seems to indicate some inside knowledge.
And we're less than two weeks from when Phoenix lands on Mars. Here's hoping it doesn't crater....
*Mom will kill me when she reads that - she wrote software for the Mercury and Gemini missions.