Well I know tap water IS easy to get in Paris , and I KNOW many locals ask for it, my french family drinks tap water at restaurants, we thought that most tourists seem to think they NEED to get bottled water as maybe they think the tap water is not good.
I also think that buying bottled water does not make one look like a local anymore then wearing all black.
Now Italy I am not sure about, but you seem to be saying that they WANT you to buy bottled water, but that the tap water IS drinkable? I feel no need to buy water to appease a restaurant where I am ordering and paying for a meal and wine already. It is not an " American" thing,( note I am not American) but a common sense thing.
I have also read about Italians charging extra for bread at the table, is this true. Seems like eating in Italy will be much more expensive then in France.