I almost deleted my comment because I think it's a bit too snarky. But honestly, I struggle with self-control issues, and can find sweet things a bit tempting. But there's good motivation to resist, because if I drank soda like water the fitness and health consequences wouldn't nearly be worth the taste.

The "cost" of drinking a whole bunch of soda is much more than the price of it in dollars. So I don't feel like a restaurant's doing me any favours by making it normal to just chug it down.