Pay-walled publications are just that: Publications that nobody reads unless someone pays the publisher’s fee. I have no problem with that, because I don’t read pay-walled work and don’t consider it published research and prior art that I should care about.
The real problem starts with researchers and editors who expect me to find, read, and consider pay-walled work as prior art. That’s an unacceptable proposition to me and an unfair one to the world.
In science, we are interested in the general advancement of understanding the world, and we should not exclude anyone through financial barriers from at least joining the game (there are already enough moats of how developed nations keep others at a disadvantage).
As I’ve said before, pay-walled work has not been published, it has been buried. I’m pretty optimistic about this: People are lazy, and if a researcher doesn’t make their work openly accessible on the web, they are at a disadvantage and won’t get cited. So open access to all research work will eventually happen.
In the mean-time, I’ll keep fighting any reviewer or editor who wants me to cite research work that’s not openly accessible.