First of all, at the time the code was drafted, broadcasters did not work alone. They hired experts in the field and commissioned studies to help prepare the code.
Second, as I said earlier, we signed off on the code. We agree with its principles. Finally, as in all cases of self-regulation, there has to be a balance between the costs, effectiveness, expertise and results. Would you prefer that the state do it all, establish the rules, regulate, interact with stakeholders, prosecute, etc., or should we consider that broadcasters are able to regulate themselves? It is in their best interest to do so because, after all, if broadcasts and programs contain high levels of violence, they will lose viewers.
Lastly, we are talking about a productive and creative industry. We wouldn't want to... How do you say that in French? Stifle...