It's true, and that's sort of the point. My "argument" (as it was firmly tongue-in-cheek) was more literal than yours, just as yours was more literal than the hammer argument. The whole idea was to demonstrate that there's always a more apt metaphor. When you get to the point where you can't find a difference, it's not really a metaphor anymore.

The best part about metaphors is not the conclusions one can draw from the similarities between two things. It's the conclusions one can draw from the differences.

Also. for what it's worth, I think that quote applies just as well to human languages as to programming languages. Perhaps the metaphor itself might make a good metaphor for programming? :)