If you start making permanent, public records of why people were banned, then you end up with a "name and shame" system. It inevitably looks mocking and vindictive, like some deliberate attempt to run these people into the ground behind their backs. That's not the image we're trying to foster here. When someone's banned, that's unfortunate, but we're not going to make ourselves look elitist and full of crap by going, "hahaha, you're GONE, but we're going to let everyone see just why your sorry hind got axed".

That sounds a bit negative, but it's the general reasoning behind the continuing choice not to keep a public note of bannings.