My guess is that it may well be another camera that nobody is buying.
We could take bets ... my guess is that the 6d will be sold a lot because...
... a) the dust-collector d600 has problems, too (and much worse low-light af)
... b) the current 5d3 price is simply and subjectively too much money for a lot of people in comparison to a lens you can get for the difference (or do other meaningful things)
... c) If you want to shoot @iso1600+ with Canon ff is still the way to go, the 7d2 next year might very well trade in more mp for still more noise.
So if you don't want to us tracking a lot, don't need the advanced features and customization of the 5d3 I don't see much against it, well, except for the Canon-like price.