Maybe for the same reason someone might say Bon Voyage. I'm not sure that is an indication that the person would expect to get killed on his trip.

you would be better off to say senza gasse or without gas

I wish people would stop saying "bon appetite", also, but it's possible that someone who didn't know how to spell that word correctly could be pronouncing it correctly. It seems so blatant to me that it would be pronounced completely differently that way, but maybe it's not if you don't know French at all. That's a pretty common phrase though, and there is even a magazine by that name. Regardless of Julia's accent, she knew some French and how to pronounce words. I don't think her accent was that bad (she had an unusual voice in general). I have a French friend who now has an American accent because he has lived in the US for about 30-40 years now, even though a native Frenchman. Now that's kind of funny, to hear a Frenchman with an American accent.

I don't think it's odd to say something like that before eating or whenever -- many countries have phrases for a toast or before a drink, for example, and some say very similar things to that. They have the same phrase in Czech, I know (dobrou chu�). It's just a way of wishing someone enjoy their meal, that's all, it isn't literal. Historically, maybe it came from the fact that a lot of people did not have good appetities in the past as they were sick a lot of the time. Also, in some countries and in certain circles, it was a positive thing to eat a lot and be larger than average, so having a good appetite was perceived as a good quality. There are lots of idiomatic phrases like that. I remember when some clerk at a cheapo cafeteria in Paris said that to me once, and then we both started laughing because the cuisine wasn't really that great. Who all is debating this in France right now, anyway?

OK, so I did spell it wrong, but trust me I pronounce it right, and I think everyone else does too. I don't know how to put a ' at an angle and over a letter on my keyboard, so figured most people would know what I meant if I spelled it that way.

But I agree that it is an odd thing to pick at -- people wishing other people a good meal. What's wrong with that and why would someone twist it to mean anything but good wishes?

It's not only italy, most foreign places I've been (not the U.S.) people wish each other 'happy eating' in one form or the other.