How would “I have a duty to hire you, but even if I don’t, nobody has a right to force me to (or, at least, to punish me)” be worth the paper it’s written on? How would a world where that’s the case differ from one where “I have no duty to hire you, and therefore if I don’t, nobody has a right to force me to”, how can I tell the difference, and why should I care?
Note that “duty to do X” isn’t necessarily the same as “if they don’t do X, someone has a right to force them to”.
How would “I have a duty to hire you, but even if I don’t, nobody has a right to force me to (or, at least, to punish me)” be worth the paper it’s written on? How would a world where that’s the case differ from one where “I have no duty to hire you, and therefore if I don’t, nobody has a right to force me to”, how can I tell the difference, and why should I care?
The question you are asking is, “what is morality?”