>It's Nikon's job to test the camera. Not the customer.
In an ideal world, perhaps.
In reality, it will never be possible for any camera manufacturer to deliver every example of every model into the retail chain with zero faults.
Once we realise that, it's just a matter of risk assessment - if a purchaser wants or needs to be sure that a camera is free of a particular problem, they need to check it themselves. That's not shifting the blame - it's just common sense.