The statist is not motivated purely or even mainly by results. Statism is not a philosophy rooted in discovery of pragmatic solutions to social problems. At the root of this kind of legislation is the belief in Society (ie the state apparatus) as a source of moral authority. The state needs to express its moral disapproval of vice and wickedness. Legislation as an expression of that disapproval is a moral and just end in and of itself, regardless of any practical impact it may or may not have.
Passing such laws is a symbolic act. Government must ’send a message’ to the flock. If it doesnt legislate (uselessly or not) it forsakes its moral authority.
I think Jay has succinctly summed up the nature of anglospheric “progressive” statism, which I think we all need to recognise is a moralist movement, as opposed to marxism-communism, which is an economics/class struggle ideology.