I'm on the fence on this issue. I would have no problem paying 2 Francs extra for a carafe d'eau if I had just a sandwich or little snack and nothing else - no coffee, no dessert - for lunch. As it is, I usually order bottled water even though I prefer tap.
However, I get seriously upset when I order a big dinner meal (as I am wont to do
) in a nice restaurant, a good, expensive bottle of wine, and then get nickel-and-dimed for tap water. I know I shouldn't take it out on the server's tip, but if I don't get anywhere with complaining to management, that's where I retaliate.