There's nothing wrong with inciting or carrying out justified violence—which is to say, a violent response to similar violence practiced by others. Your examples of murder and theft, for example. A murderer cannot rationally object to being put to death; a thief cannot argue against being fined without self-contradiction.

The problem is unjustified violence. And I agree with you that most proposals for new laws (including the subject of this article) are advocating for unjustified violence.