Interesting point you raise on the men being the exclusive discoverers (and presumbably perpetrators) of the hoaxes.
One possible exception would be the Cottingley fairy photographs. The photographic hoax was confected by young females. They became famous when Arthur Conan Doyle became aware of them, but he didn't discover them. Though Doyle was credulous, he was not a part of the original hoax.
I'll have to modify my thinking. It looks like the only people who attempt hoaxes are men and little english girls. And that doesn't actually help defend men against my premise that they are basically strange creatures with far too too much time on their hands. Adult women are just more sensible and have better things to do.