No, I agree with your point. I just take it further by holding consumers responsible for fueling that violence when they could have done otherwise, not contributed to demand by obeying the laws.
To make an analogy, it is similar to supporting sweat shop labor by buying Nikes (or whatever companies still use sweat shop labor). The argument in the case of illegal drugs is that handing over money to people engaged in violence makes it more likely the violence will continue.
If the drug trade were to be legalized, suddenly people could profit more by accepting business regulations, and violence would lower.
The point I've made elsewhere here is that it used to be producing alcohol led to violence, thanks to the Prohibition. Once alcohol legalized, businesses started making drinks rather than criminals, and the violence stopped.