Why isn publicly-funded scientific research freely available?
Life Sciences have not traditionally used the preprint archives like physics and CS has, but there is a fledgling, free, repository called Nature Precedings. Unfortunately, this is run by a major publisher and clear guidance regarding whether submission of your manuscript to this repository counts as prior publication for the purposes of sending your manuscript to someone else isn’t available.
You’re assuming that the people doing the restricting have the public interest at heart, which they don’t. When you publish something, that costs: time, printing materials, etc, etc. The publishers, which are private companies, recoup their publishing costs by charging for the published items. If they didn’t get money for the publications, they wouldn’t bother doing it and there wouldn’t be (well, 50 years ago there wouldn’t have been) an outlet for learned discourse. There are alternatives beginning to spring up, for example all PhD theses in Australia go into a national digital thesis archive that is publicly available. And of course we have the internet now, so don’t be surprised if free online publications start to appear where authors do not have to give up their copyright; the only reason these free journals haven’t taken over is credibility. The reason you publish in the closed/expensive journals is because they carry old-school credibility,
Cancer Research UK, who are a major source of cancer research funding in the UK, have recently made it their policy that any research funded by them (PDF) in any way must be deposited into the UK PubMed Central within 6 months of publication and preferably be in an open-access journal from the start. I think this will go a long way in pushing the UK cancer research community to the kind of en-masse move to open access that epugachev mentions above, even though this is a charity and not a public funding body.
As far as I can tell, nobody has mentioned this, so I will. Scientists are interested in sharing information. You can always email the author of a paper (if not actually included in the source you found the citation, their email address can be found by googling their name and university) and ask them to send you a copy. If it’s available electronically, and your author checks email frequently, you can have a free PDF in a few minutes. This is legal, ethical, and awesome. Which is to say: publicly-funded (and privately-funded, and not really funded at all) scientific research is freely available, just not from the journal publisher.
