That's only ONE example. I could go into more detail, but honestly I can't be bothered. You haven't played DCUO have you? When I used to play it on PS3, I had a window appear right in the middle of the screen saying "Such and such wishes to challenge you to a duel. Do you accept? Yes / No". Same with SWTOR. I'm not saying that IF SE did decide to include 1v1 duels that they'd use a similar pop up like the other two games have, but it would still be a nuisance. Even when you go into DF, you still get that big window in the screen, until you hit Wait or close it, THEN the smaller one pops up on the side of the screen out of the way.
Look assume all you want. If SE brings it in, I hope they also make it fair to those who do NOT want to 1v1 with random idiots. Like Enkidoh said, have the duels in one specific area and NOT in the field.