Dueling is a great RP tool to build and push forward character stories. When done right, both players gain from a duel even though one of them loses.
Unfortunately, some players misuse this tool because they are bitter OOC and want to hurt the winning side at least in some way. Losers always try to duel the winners. On every continent I have seen this all the time. Sorry, but "Someone duel me or you're all cowards" messages make the entire family no longer interesting to me. Won't waste my time on such people and won't risk my character's life.