As for the rest of your comment, I'm not sure what you think I was trying to make sound difficult. I was arguing that it's entirely possible to replace the floppy disk with an arbitrary symbol, and it's just inertia (user training and a strange sacredness afforded this one random icon) that really keeps it around. I think assosciating a distinct symbol with an action is pretty damned easy, actually. (Designing a good symbol can be hard, though.)
Of course it's possible to pick a different symbol to represent the action of saving data to permanent storage: but why bother? We have a symbol, and it's as good as any other arbitrary symbol might be. Changing it would create confusion for no benefit, since it's ultimately the association of the symbol with the action that matters, and not the history of that symbol's origin.
The younger ones don't seem to know what one is, but the older ones do.
Language is full of dead metaphor. Words and symbols have meaning because they have been given meaning; most of the associations might as well be arbitrary. Doesn't matter; humans are very good at recognizing these associations and deriving the intent.