I've thought the same thing: fan stops working, troubleshoot...hey plug's no good. Out with the wire cutters and chop the end off. New plug gets screwed on. Fan is working again.
Which is effectively what we get here with the BS1363 fused plug. Bedside lamp wired with tiny 0.5 sq. mm (about 20 AWG) cord, 3A fuse. Lamp blows, taking fuse with it. User replaces lamp, still doesn't work, so checks fuse. Oops, no 3A fuses around the house.
"Oh, shove in a 13 amp for now. I'll change it later."
Later never arrives, of course. That's if he even realizes.
Quite often it's a case of "It's a 13-amp plug, isn't it? A 13-amp fuse must be right."
