Because when's the last time you saw it used for anything? Not including the spam attacks that now make up a third of the section.
It's kind of useless nothing ever happen over there and it boils down to people spamming each other with the the same old insult. Personally i would love to see more of the mod corner debates as when they do share the debates with the rest of the forums (like for example the one between Logic and Kali dealing with Agnosticism) and they just seem to have more intellectual conversation, though I wouldn't know since I can never see this magical land of Modness and the Mods will never allow anyone to view there ideas or debates which is a shame.
Well i'm gonna stick my neck out and say it's all your fault it failed (okay, I never went on there, but that's because I don't really have anything interesting to say - and yet I still persist) Oh, it's disappeared anyway. I hope you're happy!