In podcast interviews with the FFG devs, it's come up (more than once) that a lot of folks have issue with the term 'Duty,' mainly due to the unfortunately 'doody' homonym.
Moreover, when I look at what the Duty mechanic represents, I'm not entirely sure it's even the right word. Duty is something that you're beholden to, that you're expected and required to do based on your position or the like.
The way AoR portrays the different areas of Duty, it sounds much more like it's something that the characters have decided to undertake. The book outright states that it's meant to reflect that "each of them is trying to accomplish," that it's a driving factor for them, something that a character "discovered particular talents for" or which might have been "one of the driving factors" for joining the Alliance in the first place.
Moreover, unlike EotE, where Obligation is something that's sketched out in terms of something required of the character, Duty is definitely something that, when it comes up, provides a morale bonus because the character wants to do it, because it's something that they're striving for. The mechanic doesn't have anything to do with the Alliance forcing the character to undertake this particular duty over their own desires, which again, is kind of what the word "duty" means in the first place.
I think a much better term for this would be "Focus." As in, this is the area of expertise or importance that the character actively wants to commit to, to devote their efforts toward and to, well, focus on. Also, by carrying out missions and accomplishing your goals in your area of focus, you're effectively improving your Focus score thanks to your commitment--you're not "undertaking" more duty; you're demonstrating that you're good at what motivates you, and you're contributing to the Alliance in a particular area of Focus.
Anyhow, the TL;DR version is that I'm a linguistics and semantics nerd, so when I hear that people are iffy on the term "Duty," it behooves me to point out that, based on what the mechanic is meant to represent, the term isn't all that apt anyway, at least IMHO.