It's a nice sentiment, but thanks to the Open Access movement, most recently published papers are already available online somewhere, and the people talking about #pdftribute are the people most likely to have already shared their papers. Important historical papers, even those that are now public domain, are still behind paywalls. As Aaron said, "even under the best scenarios, their work will only apply to things pu…
That is not true. I work in neuroscience and often find myself not having access to "just released" papers. Some of them may appear as preprints months later, if the author bothers to do so. I 've tried to email authors for copies a few times with no response. Even my institution doesn't provide access to all the journals we need (probably the situation is different in the US). There are actually underground websites…
And Wikipedia would kind of benefit from the historical stuff.