Why do people whose view of the world excludes a universal moral vision get their panties all in a twist over what should be an irrevelancy in other people's moral vision?
When local moralities are violated it is more offensive if it is the only morality. Because then everything rides on that morality.
People can be more open or liberal when there is a greater morality than the local.
It would seem to me that the practical attraction of local truth would the promise of laissez faire morality. Of laissez faire everything, really. How could anything be a big deal if it's just us? But I only think that because in my bones I know that there is universal truth, laid down by a universal Creator. My imagination can only tickle on the edges of a reality where truth is what we make it; the mind boggles at it more than at the idea of eternity.
Knowing that there is cosmic sense, and what is more, the cosmic sense of a Triune God, leads to tolerance. Not of everything, but precisely of the local truths, of the "my truth/your truth" mess. It can even, God help us, make us tolerant of things we're sure are evil, because we believe not only in good and evil, but in the vindication of history.
When local morality is all morality, one must be intolerant. It's a matter of survival. CIVILIZATION DEPENDS UPON IT. The only world that exists is the one we've made. A transgression against local morality is a transgression against the whole universe, because what we've made is all that's real.
You'd get upset too if it turned out people were capable of striking at the very head of your god.