Let's try another analogy. :-)
You are in the Wild West. In the street someone pulls a gun on you and fires. Do you shoot back, or do you attempt to negotiate a ceasefire? There are probably a few answers to that and some, none or all of them might be good in any given situation. How are we to judge? We would need to bring in a judge, jury and executioner. That has overheads. People would need to pay taxes to cover those overheads. Do we want that?
It would be simpler to just say that escalating to a flag at any time has a reputation cost. I'd prefer simpler. It's transparent and has a low overhead. We lose some of the nuances of a full trial I guess.