Devil's Advocate: Why should dueling be illegal?

Sometimes. Francois de Montmorency, count of Bouteville, was the champion dueler of France in the early 17th century. Before his execution at the age of 27 ( for dueling, natch ), in 1627, he was responsible for the deaths of 22 men in duels. This isn’t even including his own seconds who died fighting by his side ( the count there was more than one, though I’m not sure how many ). He is the perfect example of the worse case scenario in dueling - a superbly skilled, arrogant young asshole who baited people into death matches and caused a never-ending cycle of blood-feuds that engendered fresh duels and deaths. Louis XIII made an example of him for good reason.