I think it's because it was a name associated with an illegal act. So it had to be changed to something allowed under the law, like cannibalism.

The mods and admins have been doing quite a bit of work for you lately and you should know what I am talking about. With respect to what has been causing that work you may have a case for changing your name. But being human we also tend to react to the way people "ask" things of us and you're not getting a good reaction at the moment.

As for why KillerCannabis got a name change to KillerCannibal, is there any confusion as to who he used to be even without the notation in his location (which will be there for at least a month)? Three letters at the end of his name were changed, not even a whole syllable out of a five syllable name. That's the major reason why he was given a change to that name and not to any others that were proposed. And sometimes when someone's name becomes more commented on than their posts we like to help them out, as with Mrs.Nesbit.