 Why did the bartenders water down the Joe's drinks?
The CPA robot bartenders saw to it that anyone got high if they wanted, but comparatively few got drunk. Each bartender could not only mix drinks but could also judge by a man's actions and speech when he was on the verge of drunkenness. I've been a garbage man, street-cleaner, ditch-digger—" On the other side of the room, the jukebox came to life with a roar and a group of teen-agers scrambled to the dance floor. A civilization weary of murder, robbery, kidnapping, counterfeiting, blackmail, rape, arson, and drunkenness had originated the CPA—Crime Prevention Association. There were no longer any prisons—CPA officials had declared loudly and emphatically that their job was to prevent crime, not punish it. Instead, he was sent to a hospital where all criminal tendencies were removed from his mind by psychologists, shock treatments, encephalographic devices, a form of prefrontal lobotomy and a dozen other methods. The CPA system was, actually, cheaper than previous methods because it did away with the damage caused by countless crimes; did away with prisons and their guards, large police forces, squad cars and weapons. On the other hand, attempted murder, robbery, kidnapping, etc., were not crimes. They weren't crimes because the DCT didn't complete the act, and if he didn't complete the act, that meant simply that the CPA had once again functioned properly.
 Drunkenness was illegal.
 To avoid having to provide a room for anyone too drunk to leave.  To avoid chaos in their establishments.  To keep the patrons purchasing more and more.  Drunkenness was illegal.