I think the fact that the "worldwide publishing medium" doesn't have any of the filters that a traditional publishing medium has is a big factor. From the dawn of time up until fairly recently, it took a fair amount of effort to spout one's nonsense, unfiltered, to more than a relatively small number of people.
It seems to me that this can be viewed as a "culture" of a sort, tied to the notion of writing and publication, where there an implied responsibility to some basic notions-- Derrida, in an interview, for example, says "it should be possible to invoke rules of competence, criteria of discussion and of consensus, good faith, lucidity, rigor, criticism, and pedagogy."
It seems to me that this can be viewed as a "culture" of a sort, tied to the notion of writing and publication, where there an implied responsibility to some basic notions-- Derrida, in an interview, for example, says "it should be possible to invoke rules of competence, criteria of discussion and of consensus, good faith, lucidity, rigor, criticism, and pedagogy."