Realizing they could not pass legalization of marijuana, some people who favor that campaigned to amend Colorado’s Constitution to legalize sales for medicinal purposes. Marijuana has medical uses e.g., to control nausea caused by chemotherapy. Medical marijuana was legalized but, Suthers says, no serious regime was then developed to regulate who could buy or grow it. (Caregivers? For how many patients? And in what quantities, and for what “medical uses.”)
Today, Colorado communities can use zoning to restrict dispensaries, or can ban them because, even if federal policy regarding medical marijuana is passivity, selling marijuana remains against federal law.
Colorado’s medical marijuana dispensaries have hired lobbyists to seek taxation and regulation, for the same reason Nevada’s brothel industry wants to be taxed and regulated by the state: The Nevada Brothel Association regards taxation as legitimation and insurance against prohibition as the booming state’s frontier mentality recedes.

See the full article from “Oshkosh Northwestern”