I don't know where people are getting the idea that 1 million copies sitting on shelves is too much.
Also, notice that it's not just copies sitting on shelves. There are also copies at warehouses and in shipment (i.e. sitting on ships or trucks).
Next week it will sell less than 200k if it stays at that rate 6 weeks worth of stock is a lot. I assume it will drop to 100k the next week and that would be 10 weeks worth of stock....