The comments from the users of the site are still flooding in, and almost all of them are...
panicky: "OMG, where am I going to post my shitty self-insertion fics now?"
angry: "OMG you fuckers, where am I going to post my shitty self-insertion fics now?"
petulant: "OMG, I'm going to pull all of my shitty self-insertion fics and post them to a place where they appreciate shitty self-insertion fics."
denial: "They're not serious, this is a joke right? I'm so depressed."
activist: "This isn't right. I demand that you let us post our shitty self-insertion fics. Everybody sign my petition."
The overall theme of the thread though was one of self-entitlement. There was a tacit suggestion (though explicit in at least a few of the messages) that the free, volunteer-run site somehow owed them something, and that the administrators needed to just shut-up, do their jobs, and be thankful that people chose to post their shitty self-insertion fan fictions on the site.
Here is a long depressing read to help quench any faith you might have in humanity.
The site owners seem to have taken it all in stride - I am pretty sure this was the kind of reaction they were expecting. They have a history of being shit disturbers, so they are used to it.
On the other hand, this served as a bleak reminder to me of why I am reluctant to volunteer my time for sites like this. I am not a big fan of human nature sometimes, and I don't think I would like being on receiving end of this flood of angry, self-entitled ingratitude.
"How dare you give the fandom a gift that does not cater more exclusively to my wishes! I demand you improve this gift until it meeds my exacting criteria. Now!"
I will grant that it was a slightly dickish prank, since they knew that it would generate this kind of fevered reaction and panic, but at the same time they owe these people nothing.