For me, one of the big benefits of working at a university was access to its library and in particular to its online journal subscriptions. I had hoped that by the time I retired everything I might want would be open access. But then we moved to the UK and I gave up my job...
The Bodleian is a wonderful library system, but as an external reader there are two major limitations: I can't actually borrow books and I can't use Oxford University's online journal subscriptions.
This is less of a problem in the sciences, where preprints are often (though not always) available, either through something like arkiv.org or informally through author web sites. But this culture doesn't seem to have reached very far into the humanities, where I find most of the research I want to read is not so accessible. Fortunately I know enough people who do work at universities that this is not a problem, but the possibility of losing access to all of this is disturbing.
More abstractly, every time someone hits a "this article will cost you $35" web page and (as they mostly will) gives up, that's a deadweight loss (as the economists call it) and a setback, however small, for human scientific and intellectual progress. My initial exposure to copyright and patent issues came through free software, but for me the arguments for open access research and science are actually more compelling. And, as with software, for me the moral and political arguments here seem as important as the economic or technical ones