Earlier quoted context omitted.
There's also the British penchant for deliberately mispronouncing French words. I have heard "renaissance" pronounced "reh-NAY-sance", "fillet" pronounced "fill-it", "valet" as "val-it" and so on. I think it's a national point of pride to pronounce the words of their neighbor incorrectly.
America is at least as guilty of mispronouncing non-english words it's just natural drift. As to fillet and valet, they joined english before the contemporary french pronunciation, and are much closer to the middle-french.
My favorite is probably crepe, which Americans pronounce like an almost diphthong-y craype (or crape like grape I guess) when crep (like step) would do just fine and be closer to the original.
But as a native French and basically-native American speaker, I also couldn't really care less about it, or about things like Americans pronouncing the t in croissant, or French people being unable to say the.