So why is the practice continued? Writing in Times Higher Education, Les Hatton and Gregory Warr identify various problems and then observe:
We are not the first to identify these problems, so we might ask why peer review retains its essentially unassailable status. We suggest a two-fold answer rooted more in socio-economic factors than the dispassionate review of scientific research.First, peer review is self-evidently useful in protecting established paradigms and disadvantaging challenges to entrenched scientific authority. Second, peer review, by controlling access to publication in the most prestigious journals helps to maintain the clearly recognised hierarchies of journals, of researchers, and of universities and research institutes. Peer reviewers should be experts in their field and will therefore have allegiances to leaders in their field and to their shared scientific consensus; conversely, there will be a natural hostility to challenges to the consensus, and peer reviewers have substantial power of influence (extending virtually to censorship) over publication in elite (and even not-so-elite) journals.
Yep, sounds like the humanities (see my post Rejected @NLH! Part 4: Déjà vu all over again at New Literary History + Welcome to the club, Franco! [#DH #Canon/Archive]).