No right without a duty?

I stopped skimming these no-right-without-a-duty links when I
encountered the facile point that the "duty" inherent in a right is to
not violate the corresponding right of others. I don't see how it helps
to say that, e.g., the right to life imposes a "duty" to do something.
If that "duty" is simply not to murder people, then it's better not to
talk in terms of "duty", but rather in terms of equality of rights.

The distinction between positive and negative rights is one of the most
powerful analytic tools in the arsenal of modern libertarian theory. In
modern political discourse, to say "every right imposes a duty" not only
discards that tool, but nearly concedes the central debate by framing
the core question in terms favorable to those who advocate positive rights.

The only broad positive obligations that the Libertarian Party should
recognize between individuals is that of guardians toward those in their
custody. Many Libertarians also advocate some narrow positive
obligations, like jury duty or to testify when called as a witness by
the criminally accused, but it's uncertain whether a supermajority of
NatCon delegates would agree to enshrine these in the Platform. Some
constitutionalist libertarians also advocate broader positive
obligations (e.g. militia duty) based on social-contract theory, but
those ideas currently have nowhere near enough support to get into the
Platform. I too advocate some ideas that don't (yet) have enough support
to get into the platform, like the geolibertarian right of equal access
to the natural commons of the Earth (land, water, air, minerals,
wildlife, spectrum, etc.).