If my wife was raped and murdered you think it would be more moral to punish me than the murderer because I want vengeance?
But if you take steps to conspire with people to cause violence to be caused to others, such as by voting for the perpetuation of a violent, brutal prison system, then I would see you as morally no better than someone actually engaged in a violent attack. You're in that case seeking to cause an untold amount of harm to others.
To me, seeking to cause that to happen to others is at least as wildly immoral as a rape and murder.
> I find the notion of supporting this level of harm to others to be no more moral if you vote for it than if you commit a violent crime.
I likewise find it pretty ridiculous to equate voting for retributive punishment for murder and actual murder.
Personally, I find it ridiculous to differentiate between murdering a person for e.g. money, and murdering a person for vengeance, and absent an imminent threat for which deadly force is generally authorized, I don't support the use of it.