The speaker insists that a community must tell its own history, because nobody else is going to do it properly. The poem names three ways outsiders fail them: they "speculate," they "manufacture," or they ignore the group entirely, hoping it will quietly "go away in time." That last phrase is the coldest moment, because it suggests people waiting for a whole people to disappear.
The first line has "stones" where we might expect "stories." That could be a typo, but it can also be read as a deliberate slip, since stones suggest memorials, graves and things that last. The poem then corrects itself to "stories" in the second stanza, as if the speaker were moving from monument to living voice.
The mood is quiet, firm and a little weary. There is anger under the plain wording, but also determination. The short final lines carry the heart of it: telling is how memory avoids dying "with us." The title, "Ourselves Alone," sounds both lonely and defiant.