Home Plate on Lombard Street in San Francisco has a similar policy, reported SFGate. Signs posted around the restaurant and on the menu asked diners to "Please Drink Responsibly. $50 cleaning fee per person for any incident incur as a result of intoxication."
Other brunch restaurants in the Bay Area use "mimosa fairies," servers devoted to monitoring the intake of guests.
Which type of liberalism is this? 
With "something to drink" type drinks nobody cares if they're tasty as long as they're not actively unpleasant. Nobody will be mad at you if you bring some white claws or knockoff ices to a party; they're just upscale piss beers. I'd feel bad putting genuinely nice rum into a glass of coke.
Fair enough, but "shitty" rum and coke is miles better than whatever grain liquor they use with the whole lot of sugar in it.
I guess it's not for me, but I totally understand bringing some smirnoff ice or white claw to a party/picnic.