Banning something has never done anything but push it underground.
True, but that's not always a bad thing. Some things that are pushed underground happen a lot less. Murder, for example, is banned. Instances of it are (often) vigorously investigated, and the perpetrators dealt with (to varying degrees of effectiveness). I suspect that if murder was not banned, it would happen a lot more.
You're right but I'd wager that the more educated and therefore better equipped someone is to express themselves in non-violent forms of communication the less likely they are to commit murder. It's also no coincidence that murder is a more prevalent crime in poorer societies. If people have better opportunities and something to lose they are much less likely to throw it all away in a fit of rage. They are even less likely to enter into a fit of rage in the first place as they will be more contented in life.
True, but that's not always a bad thing. Some things that are pushed underground happen a lot less. Murder, for example, is banned. Instances of it are (often) vigorously investigated, and the perpetrators dealt with (to varying degrees of effectiveness). I suspect that if murder was not banned, it would happen a lot more.