Dueling is a practice that is integral to freedom. Without the right to duel someone who has violated a social contract, insulted ones honor, or to settle a legal matter out of court, we are limited in our autonomy.
With clearly defined dueling procedures, dueling is an honorable and serious practice that can settle matters that simply can not be settled in any other way.
While there possibly must be some restrictions (for example, duels with firearms in heavily populated cities should take place in designated dueling areas to eliminate 3rd parties getting shot accidentally, although swords are fine anywhere) the restrictions can be simple and noninvasive.
We are free adults in this country, we deserve the right to duel if we want.