said by cowboyro:One word: WANT.
Not all people need to save water. In many places water is too cheap and too abundant to worry. Even a 30min shower would take far less water than what is needed for 1 day of lawn irrigation.
One word: MARKETING. And another word: SUCKER! Despite what the warranty says, I suspect that there may never be a day where this thing DOESN'T leak from somewhere.
I live on top of one of the best and largest aquifer systems in the world, plus next to the Mississippi River and several smaller rivers, so water here is abundant and cheap. Yet we are constantly reminded not to waste it, and they bend over backwards to protect the aquifers - to the point of stopping you if you try to build the wrong type of facility at a geographic point where contamination would be easy. So we all try to be good citizens about this.
On the other hand, I was in Chicago last year (near the lakefront) and my hotel's shower put out so much water that it nearly knocked me off my feet. And I'm not gonna lie about it - it felt good, man, it felt good!