I used to work at a retailer and I know the password myself.
This is a prime example of hyperbole. The password only allows you to change things like what is printed on the receipt (the banner), merchant ID and other such things. It basically allows you to enter into a menu to set a few settings. It's not as if you can get a dump of card swipes.
Just a few researchers spreading fear about what has been known for a long time.