This is not the same Nikon I knew in the 60's and 70's and I have been using Nikon products since 1963. Service was first class and I cannot understand what is going on now with their customers service.
The D600 had issues with dust from its introduction and as your article says it was not addressed entirely. I would not be surprised if some of those that sent their cameras were charged for parts or for replacing the defective shutter. For some reasons, I have seen more problems with cameras coming from Thailand than from those coming from Japan.
I do not rely on Nikon anymore for the repairs of my gear and instead I send it to Authorized Photo Service in Morton Grove, Illinois.
First quality service at reasonable prices.
Which brings to mind when buying Nikon, I'm leery when purchasing a body or lens and it's not from Japan. For instance, just purchased a Nikon 105 G f/2.8 micro, made in China...it fails to go to f/2.8 quite ofter. Don't know if this is usual or not, but my more expensive lenses (made in Japan) don't behave in this fashion. My D7100 is made in Thailand, starting to think I'm driving a mutt.