Other people have addressed the catch about prestige which makes this difficult. There is often some amount of cost, even if editors 'donate their time for free' (which, of course, is usually the case even for the traditional journals - the copy-editors are paid, but the content editors often do it for free, because it's a prestige economy). But individuals have created true open journals, like Glossa (mentioned in the article) and Semantics & Pragmatics ( http://semprag.org/ ), which are in fact prestigious.