It seems like one reason to try to mark off a distinction between pragmatis and semantics is so that one can tell when pragmatics can be used to account for a phenomena and when semantics should be used. A lot of semantic theories (and fragments) seem to treat pragmatics like this buffer that absorbs and accounts for all problems with a semantic theory. It is hard to argue against something if it can always be defended by an appeal to some vague, pseudo-Gricean reasoning. Of course, the distinction between semantics and pragmatics might be theory-relative so that it will be impossible to produce a single, comprehensive distinction.