The "which program you use" confusion was instigated by the idiots insisting that we should have metric kilobytes, megabytes and gigabytes (cheered on by crooked storage manufacturers).

Before all that nonsense, it was crystal clear: a megabyte in storage was unambiguously 1024 x 1024 bytes --- with the exception of crooked mass storage manufacturers.

There was some confusion, to be sure, but the partial success of attempt to redefine the prefixes to their power-of-ten meanings has caused more confusion.