People like Stan and I (and the other Mods here) have been dealing with this type of situation for a number of years now. Whenever a new camera is released, there is a consistent pattern of some owners complaining about a perceived problem that turns out (after some careful guidance from our members) to have been caused by something other than a faulty camera. That doesn't mean we automatically assume the user is at fault - we try to look for solid evidence before making a recommendation one way or the other.
Fortunately, we tend to get fewer "trolls" here than at some sites - and I certainly don't put this thread in that category - but until we see the results of some more rigorous testing, it's difficult to believe that three randomly-obtained cameras suffer from exactly the same mis-adjustment, especially when other recent owners don't see anything wrong.
I would also need a lot more evidence before agreeing with your guess that newer examples of the D7000 are all leaving the factory with a problem - though as the D800 "left AF point" situation has shown, anything is possible