I have nothing against paying whatever a restaurant wants to charge for its menu items. The prices are listed; if I think they're too outrageous, I can choose to go elsewhere. But in addition to what's listed, certain assumptions come along with the dining experience...and if a restaurant is going to do things differently from those prevailing assumptions, it ought to both have a good reason for doing so and be sure its customers know about it.
For whatever reasons, in the last five to ten years, nearly every restaurant has gone over to the endless-refill model where soft drinks are concerned. One exception is fast-food places that have the fountains behind the counter...but even there, many of them offer refills free or at a nominal charge. Your typical fast-food or fast-casual restaurant nowadays has the soda fountain out on the floor, where customers can fill and refill beverages themselves. Even most sit-down places will refill your soda for free, many times without asking, many times taking away a quarter-full glass just for their own convenience. How can they afford to do this? Having worked one summer for Pepsi delivering their product, I know that the answer is: because soda is dirt-cheap, particularly the fountain variety. Restaurants are still making good profits on beverages, and it's to their benefit to keep customers happy by offering free refills.
So what's the problem with the few holdouts? The other day I was at a place, and as usual, when my diet Coke or whatever was empty, the server returned, asked me whether I wanted another one, and went off and returned with a second soda. So it was slightly irksome when I look at the bill and find that this is one of these places that still charges for every individual soda. It's not as if I can't afford the addition two bucks - but I can't escape the impression that, knowing as the place must that most restaurants nowadays do not charge for additional sodas, the quick service on the second soda is a way of driving up the bill - and along with it, profits. It'd be one thing if this place were charging some superlow price for soda - but as I said, it was a fairly typical two dollars. I didn't say anything about it - I'm not that cheap - but hey, it's just a little bit annoying, and a small little addition to my collection of peeves.