That's not true though.
The bottled water usually tastes much better than the tap water that's often highly chlorinated, and it's convenient - not just in the sense that it's easy to carry around, but also in that it's easy to find and get access to, because you can buy it pretty much anywhere you go, anytime you want.
If I'm visiting the city, or even out on a beach, I will not be usually be able to find any freely available drinking fountains. Usually the only place I see any at all are gyms, schools, and older parks. If I didn't pack any water with me? Well, too bad for me.
People have more than a few very valid reasons for buying bottled water - if they didn't, they wouldn't buy it. You want to change that, start looking at why people buy it in the first place and start tackling and solving those problems/demands that corporate america saw, exploited, and fixed.