Modern people like to think politically almost exclusively in terms of rights as opposed to obligations. Framing politics in terms of "rights" makes it seem as though there is a progression toward greater human freedom as more rights are recognized. More rights (the unreflective modern presumption goes) means more freedom.
But this is only illusory, precisely because one man's right is necessarily another man's obligation. One man's right discriminates between his substantive claim and some other man's substantive claim. One man's property right is another man's trespass. Every political right carries with it an authoritative discrimination, backed by the full force and credibility of the government, between some set of substantive claims and some other set of substantive claims. A "right" by its very nature asserts authoritative discrimination.
And this is neither good nor bad as a general thing: it depends upon the actual particulars of the discrimination enforced by a particular right held by a particular person. Some discriminations are, as a substantive matter, good and appropriate: e.g. the discrimination between owner and trespasser. Other's are wicked and inappropriate: e.g. race as a determinant of severe punishment versus a slap on the wrist. We can't really know without knowing the particulars.
And lets not kid ourselves. Every assertion of a right on the one hand entails an assertion of obligations on the other. So the notion that "more rights means more freedom" is sheer nonsense. More rights means more particular, varied, and complex obligations: it means fewer degrees of freedom in the phase space of available human options, not more degrees of freedom. That may be a good thing in many cases, depending on the particulars: human beings often need to be confined by positive rules within a smaller sphere of available options. But the notion that more rights implies greater freedom is balderdash. If anything the very opposite is true.
So confining political discourse to obligations rather than rights (over which obligations supervene, though the reverse does not seem to be the case) isn't just a matter of semantic preference. It is a matter of being honest with ourselves.