There are two different management styles. Most companies operate around a release date. So Ubisoft tells a team to make AC4 and it must be done by XX date. That teams makes what they can and releases it. If they leave out things, or do less QA, that's what must be done. They may probably have a good estimate of the time it will take because its an annual release, and they may put in OT, etc to get it done, but it's management toward a date.
Nintendo manages toward a product. When the product is done, it is released. Do whatever it takes to make the product as good as possible, and then it will be shipped. I prefer this style, though it is nice to no AC4 will be available in October. Several other studios follow this mantra, Blizzard being a notable example. Games with outstanding quality tend to be made in this way. It's why Nintendo, Blizzard and others are held in such high regard.
I would say right now there are probably some pretty strong internal deadlines at Nintendo. I would imagine that the MarioKart team knows that they need that title out this Christmas, and several others are on ASAP notice. Pikmin 3, however, I think was never thought to be a system seller and is more of a pet project of Myamoto. It's probably done by a small team that doesn't have the resources to speed things up.
