Preface: I am a great supporter of open access, and I agree that most arguments against that model are bunk. Given a choice, I would pay more and publish in an OA publication. At the end of the day, though, whatever hidden costs their may be do not directly manifest themselves to the author, closed-access is still cheaper than open access for immediate out-of-grant-pocket expenses. Page charges nonwithstanding. If one is fortunate enough to have an extramural grant that is budgeted for OA publications, then that works fine. If not (and many do not, because small size grants don't have enough bandwidth for the expected $2500/yr or there is no grant and you are running on institutional funds, as happens in many R2 universities) most groups would rather spend this money on research and/or student stipends.

Yes, most journals would waive the fee if the author claims hardship. But most authors would not claim hardship: they have the $2500, they would rather give it to a summer student. So they would go with an equally reputable CA publisher, maybe pay $500 in page charges.

The cost-benefit of open access is still unavailable to most people, but the OA advocates do not seem to realize it. Unless you have have an R01 with OA charges in it, you have no compelling reason to go with OA. Ideological support for a laudable cause nonwithstanding. Yes, the ideas are great. No, the immediate benefit is not apparent. Maybe the library overhead does may CA more expensive in hidden costs than it is. So? It is still there!

Point being: most of my colleagues would not publish in an OA journal due to the cost. In fact, all they know of OA journals is that they are expensive. OA seems like a fringe benefit, especially in the current promotion and tenure criteria in universities.

Bottom line: there is between OA advocates and a large part of academia (which publishes CA), analogous to the one that exists between open source advocates and the rest of the world (which uses Windows). There is a fundamental misunderstanding of what OA is about, and the lack of ability to convince people to pay for it when CA is perceived to be cheaper.