I never said that by only cutting frivolous usage, the problem would be solved. If 80% is agricultural usage, then agricultural cannot be not part of the solution as well. But if people keep coming up with clever arguments for not cutting their favorite usage themselves and argue that others are at fault, nobody will do anything.

You are looking at the problem from the perspective of which cuts will bring the usage down faster. I am looking from the perspective of which cuts will produce less cost to society. Each point of view lets you highlight some aspect of the issue, and obscures many others by necessity.