It's supposed to just be a fun event.

It's supposed to brow beat men for being men. It's meant to humiliate, demoralize and debase them. That kind of bigoted abuse of an identifiable group has no place in society, much less the armed forces. The organized othering and ostracization of an identifiable group based on an immutable quality is a precursor to genocide. Those behind this shoe stunt should be serving life sentences for crimes against humanity. And those military members who participated should be charged for (at the very least) poor dress and deportment, even if they were given "permission" to do it while in uniform. If "I was just following orders" wasn't a good enough excuse for the Nazis at Nuremburg, it's no excuse for these guys either.