Well, first, no; French actually does make a distinction between the animal and the meat. We don't eat "vache" ("cow") or taureau ("ox" or "steer"), we eat "bœuf" ("beef"), to use your example. But that's not really related to this discussion.
My apologies; I had it backward. It was in English before the Norman conquest that no distinction was made.
The point is that "tart" and "pie" are synonymous in English unless you make weirdly arbitrary distinctions between upper crust and no upper crust, which goes against common usage everywhere in the English speaking world (except in arth's house and maybe parts of Oz?). Which is probably because of etymology (i.e. the French provenance, in this case) or maybe (and this answer is simple and makes more sense to me) just because the conventions in European baking terminology are French.
It's not true, though, that it goes against the common usage, at least not in the United States. The use of 'tart', at least, is, in fact, almost always restricted to pastries without a top crust. The restriction of 'pie' to items with a top crust may be changing, but I have never in my 40 years heard a pastry with a top crust referred to as a tart.
And, of course, Art was at pains this time to say that he was expressing his own usage preference, which makes any attempt to accuse him of pedantic prescriptivism rather pointless...especially when one's basis for the claim is a tenuous etymological one.
