More and more of this depends on the fact you have not done any research. Apply your Earth bound common sense to a lunar situation. Many of the hoax theories are the result of applying what seems like common sense on Earth to the Moon. Things on the Moon are weird. Many of the weird things that hoax-geeks claim are faked practically prove they happened on the Moon.
People love a conspiracy.
Same reason that people believe them, they like to make them up. Particularly if you can then sell your theory to others. I think there's five reasons. People are stupid. Sad, but true.