You need to have evolutionary pressure to have directed evolution, and "alcoholism is a disadvantage" is as good as any. By drinking more, one reduces their and their kids' chances to survive, making those alcoholic genes less frequent.
By the way, I hear propensity to alcoholism is also an inheritable trait.
I just mowed (parts of) my lawn. Left some clumps of different wildflowers standing, dandelions included.
I'm glad my neighbourhood does not have a Lawn Enforcement Agency.