The journals that publish those papers are, in many cases, for-profit institutions — and they prefer charging for access.
The (TAXPAYER FUNDED) National Institutes of Health, which spends about $30 billion yearly on medical research, began in 2008 requiring that research studies it funds be made open access a minimum of one year after publication. The Gates Foundation now requires that publication of the research it funds be openly accessible by the public starting now and for, like, ever–meaning that publishing in big brand name subscription-only journals might be off the table. This puts pressure on those journals to provide open access. HOORAY! Science evolves!
At the moment clinical research is the area of study least likely area to be open access. The community hospital I work at provides its clinicians no scholarly resources. My school bestie and I our putting our thesis where our mouth is by choosing to study and promote access to clinical resources for staff nurses…despite being told by every adviser we have that it’s a bad idea. We may (probably will) go down in flames, but sometimes the amount of push-back you get is proportional to how right you are.
Ethical problems crop up in establishments that sustain themselves by limiting access. Closed institutions embolden those with access to manipulate those without, provide a nice incubated broth for corruption, weaken the rigor of their founding principles, and encourage opacity to protect against anything that might devalue access.
Am I talking about academia? The journal Nature? Fraternities?
If you opt for open access and promote a culture of transparency you’ll get two things: 1.) Diffusion of knowledge making fertile ground for creativity and innovation, 2.) Confronted with the fact that there’s a lot of bad wood underneath the veneer. Which is the first step in getting that rotten stuff out of there.