Personally, we leave quite a selection of drinks. Water, flavored sparkling water, a couple diets, and non diet soda (we shop at Costco so the variety always changes). A can of soda vs. a bottle of water does not cost much different and the variety shows a higher level of detail and care that you put into hosting.
Sure, providing a few extra drinks cuts on margins, but in my experience the more detail and care you put in the "extras" the more people appreciate their stay and write a fantastic review, which in return allows us to charge more than others in our area. I will pay more to stay at a higher quality place than to compromise a crappy stay because a host cared more about margins than their guests.
Also, to go off the mini fridge specifically, we have a Keurig, snacks, and we always have q-tips, cotton balls, extra (pre-toothpasted in wrappers-Amazon is great for these) toothbrushes, razors, soap, shampoo, and conditioner. Things that people may commonly forget. These details and making a place feel like a home away from home is what Airbnb is about.
I've also noticed the majority of guests do not eat or drink or use ALL of the items and to be honest most hardly take any (apart from coffee). Only a rare few have eaten and drank everything.
When you make it feel like home, guests will treat it with respect.