Ok..I take the point that IEC leads are designed to be detachable, however, if the equipment no longer works because the fuse has blown in the mains lead - surely that indicates a problem with the equipment .... does it not?
Something has caused the fuse to blow ..it needs investigating not randomly swapping by a non-technical person.
As for fitting a 7 amp fuse in everything! - most manufacturers actually specify a fuse rating for the plugtop.

Sometimes the gene pool just gets muddy.