It's a business- if people are stupid enough to pay their prices, it's OK. Why does water need to be purchased? Get a filtered pitcher or a whole-house filtration system and use a stainless bottle.
As far as water being a "right", no- it's a basic necessity. Do you mean that clean water is a basic, human right? How do you justify this when major populations on the planet don't have access to clean water? Who should pay for this clean water? The countries without it can't afford to pay- should the rest of the world pay for it?
Feel free to comment, but I'm not trying to be argumentative, I'd just like to know why a business that provides a product to people who are willing to pay for it shouldn't profit from it. What about all of the water they donate when a storm, earthquake or other disaster occurs? Doesn't that count?