Government policy and law exists to improve the life of its citizens. Those creating the laws and setting the policy should, and usually do, take it as their mission to make things as good as possible for all of their constituents. The biggest issue with making policy is not that people want to make things worse but rather that they persist in making decisions based on ideology instead of fact. The war on drugs is a great example of this in action - governments funnel money to organized crime, spend enormous sums on enforcement, and imprison people for victimless crimes without ever stopping to think that their schemes simply aren't working. People still regularly use drugs and can get high any time they want so what is the benefit in trying to stop them?
I saw a great little video on the BBC today about the second great example of this: Prostitution. A blogger who talked about her escort work for years is interviewed about her attitudes towards prostitution and policy surrounding it. The interviewer continually tries to make the case that prostitution is bad but never even attempts to attack the *efficacy* of anti-prostitution laws, which is the only thing that matters. We know that making seatbelts mandatory works at reducing deaths from car collisions so it is a law worth having. Laws against prostitution don't work and cause all kinds of problems like funding organized crime and encouraging human trafficking so we shouldn't have them, idealism be damned.
Now I don't buy the idea that prostitution is wrong in the first place but we don't need that to feel that criminalizing it is wrong. Should we regulate prostitutes to some extent? Maybe have licences or get them to register or something to attempt to control the spread of STIs? These are conversations that are worth having and honestly I don't have the answers. Should we put prostitutes or johns in jail though? Absolutely not. We always should be looking at the results of our laws and not allow ourselves the luxury of wallowing in idealism while ignoring what we are actually accomplishing.
It is quick, easy, and clean to moralize on someone else's life choices and declare them worthy of punishment. It is much harder to figure out if government interference would actually help the situation or merely be an expensive nuisance. We owe it to ourselves to make our decisions about real effects, not idealism, because it is the real effects that matter. Senseless, ineffectual prohibition may make a few people happier because the state officially does not sanction an activity they find unpleasant to contemplate but government doesn't have the mandate of salving people's consciences. They have the mandate of making things better for all of us and they should keep that in mind.