Smeags on 01 November 2013
I blame D21Lewis.
But seriously though, it's a really unfortunate turn of events. I'm betting that the issue was exacerbated by Pokemon X/Y and how you can become friends with complete strangers just by trading/battling with them (I was quite surprised on how easy it was to become friends, especially for Nintendo 
).
Hopefully this means that we'll see 3DS Miiverse functionality soon, but it's still unfortunate that this great little app was cancelled because of a few bad apples. 
