Water treatment seems like it should be a pretty solidly-researched and standardized thing. Granted, for most of our history obtaining water has been completely different – natural sources (rivers, lakes, etc.), rain, wells.. modern plumbing is relatively new compared to all of that. Even looking at it like that, we've been doing this long enough that water should be – water.
If I can go to a major city and get good clean water out of a faucet, why, here, do I have to choke down water that either tastes overly metallic or reaks of chlorine? I guess most people don't really care, but I'd really like to have easier (faucet) access to water that doesn't taste like other things.