Are Linguistic Journals Tombstones?

Paul Krugman notes (here) that within economics, dissemination of research is  is not via the journals.  Rather these act like repositories (he calls them 'tombstones') of stale information and is used mainly for "validating your work" and citable "when seeking tenure" but not the place to go to "keep up with what's happening now." I've tended to regard ling journals in the same way: their prime function is not to lead the investigative pack, but to bless work that has been done.  However, given the time and effort generated to reviewing, editing and publishing journals of record, it behooves us to consider whether or not all the effort is worth it. If the aim is to support research, it seems that far less formal venues are already doing most of the heavy lifting.  How important are journals in this context and are they worth the time, money and effort demanded? Are our journals mainly a service for deans and university presidents?  Would their importance go to zero were tenure to disappear?  Just asking.