Where are you getting these 6A plug fuses? 1, 2, 3, 5, 7, 10 and 13 are the ratings I know of.
This discussion is about domestic appliances made to recognised standards and designed to be used by unskilled persons, not components of an electrical installation. Are you saying the instructions require the fridge to be installed by a competent electrician, even when simply being plugged into a socket outlet using the supplied plug?
Modern appliances are intended to safe when protected by a B16 or 16A gG fuse as this is what they will have in many countries. Outside the UK, the appliance flex and plug are protected against short-circuit by the same 16A MCB in the board that protects the wiring against short-circuit and overload. The appliance must have its own internal protection against overload. In the UK we have 13A sockets on 32A circuits so one OCPD can't protect both, requiring us to put a fuse in the plug as well. But for the most part, that is what the plug fuse does; deals with the discrepancy between a 32A circuit and a 0.75 - 1.25mm² flex.
By all means put 1A fuses in your lamps and 5A fuse in your toaster. There are no surges to consider and no harm in it. But the thread was about the specific case of a hermetic refrigeration compressor that can have a high stall current under abnormal restart, that is equipped with a Klixon to prevent overheating and a flex suitable for S/C protection at 16A, and for which the manufacturer recommends a 13A fuse. Here it makes sense not to go as low as possible simply to reduce the splash in the very unlikely event that the flex gets crushed.
