As of right now, the CBC is running an online poll regarding bottled water. The question asks whether a cardboard box of water is better than the current, commonly used plastic bottles. One of the responses, and the most popular response, is "What is wrong with tap water?" Well, that's a good question, and something that deserves more than just a pithy comment on an online poll.
In your home, nothing is wrong with tap water. It's there, it's piped right to your sink, it's generally safe to drink. People might even have a reverse osmosis system built right in if they're picky about the water itself, and that's pretty useful. So naturally this is not going to suggest that there is anything wrong with tap water as a delivery system.
Bottled water is useful because it's there where there are no taps. Planning on exercising outdoors? You're going to need water, in a bottle. Naturally, the smart solution is to just fill up at home in a reusable container, but if you're perpetually poorly prepared, like this writer, picking up a bottle of water on the way is going to be the next-best solution. Going to the lake? That's a fun activity everyone enjoys in Canada, and while there are other liquids in bottles that can be fun, it's a good idea to have water too, and not every campsite has potable water.
There are a ton of reasons why bottled water is a good thing to have, and most of them involve events, activities and outings where a tap simply isn't available, or the quantity of water that needs to be distributed rapidly would outpace the tap. A marathon needs you to get some hydration to runners quickly, and a tap isn't going to be convenient for that. An emergency needs people to get water to a lot of people fast, and bottled water is good for that too. Is a town under a boil water advisory? Well, break out the bottles, and everyone can have a drink without turning on the stove. Generally, bottled water is a good solution for those situations where a tap will not work.
This isn't to say bottled water is perfect, waste is the main issue. Recycling needs to be a priority with the container, especially given that bottled water is going to be most useful in the most remote areas. People just tossing their empty bottles everywhere are a primary reason why so many are down on the stuff, and if you could go hiking without finding a bunch of discarded plastic people might be more accepting of the stuff.
Some people also don't like the idea that people are sold a product that is delivered to their home anyway, for cheaper. That makes sense, especially if you find over-priced designer water, but honestly a distrust of companies marketing water doesn't mean the entire concept of water in bottles at the local store is a bad one. The product is useful, whether or not you like how it's sold.
When people object to the idea of bottled water, they are making a statement about many things outside of the water itself. They find it wasteful, or they find the marketing distasteful. That's fine, but that does not make the entire product category something to discard. It's just up to consumers to be smart about whether they need it. There might be nothing wrong with tap water, but bottled water also has a place.