I think the field of physics is more advanced on the publications front. Unfortunately for medicine, biology and regenerative medicine we are way behind. Our field is structured in such a way that if you don't publish in some of the "prestigious" (for-profit) journals you are not taken seriously and it's not easy to obtain funding. The only way to change that is if the funding agencies start introducing some strict requirements about publishing the research funded with public money on open access journals. The governments should also regulate the publishing industry. If the for-profit companies want to charge for the articles must have to pay to researchers that review and do most of the work for them or at least be forced to reinvest part of the proceeds in funding reasearch since they generate multi-billion dollars every year, too much if you consider that who does the work for them gets nothing.
I think it would be ok to volunteer our time if the organization is non-profit, but the publishers make so much money they should contribute more in the field.