Would you pay extra for ultimate QC?

Most people do not even understand QA/QC so I'm not sure what they think they'd be getting for this "ultimate" QC.

Many of the problems that we see as consumers show up only under certain circumstances and sometimes at a fairly low rate.  Pre-release testing often does not catch these defects.  Certain defects are the result of a faulty procedure or a faulty piece of equipment.  Sometimes this defect can be intermittent, not every camera off the assy line is tested and it's possible for these defects to slip through final QC.  It can be as little as machine operator 'C' isn't following the calibration procedure properly.

QC is a huge process, from vendor parts to internal processes to final assy.  Some things may appear that they should obviously have been caught but they aren't.  A product can pass your test and still have something wrong with it because your test doesn't accurately simulate how someone will use your product.  This only covers defects that are present when the camera leaves the factory, your camera could still break in the first 100 shots and there's no way for QC to catch that.

One might wonder how a camera like the D600 can make it out the door with such a huge dust/oil problem but we don't have the real numbers to tell how significant a problem it is.  Was it an engineering/design problem?  Is it a problem with a vendor part?  Is it an assy process issue?  Who knows.  No product has a zero defect rate and no company intentionally produces a defective product because it will cost them much more to fix it after than it will to fix it before it leaves the factory.

Manufacturers usually have a "cost of quality" that they track, I'm sure Nikon knows how significant an issue these problems are.

I work in manufacturing, i just finished auditing a Quality System.  I know how problematic things can be, I know there is often a difference between what you should be doing and what you actually do. Any time people are involved, things get screwed up