Let's not get into estimating the actual percentage of humanity that lives within, say, thirty minutes of a publicly accessible library with a Nature subscription. (I do, but I pay big-city rent for a reason.) Instead, let's talk about modern information technology.

Have you ever visited tvtropes.org? Don't go if you don't have the rest of the day to waste. It is seriously addictive, mostly because it's a sterling example of hypertext in action, maybe even better than Wikipedia. Every article is linked to the others. Every citation has a link. You want to check a reference, you click. You want to surf a chain of references N generations back, you click N times. You can't not follow the links on tvtropes.org, unless you simply hate all pop culture.

It is the height of irony that HTTP was originally invented to link up academic publications, because when last I surfed academic journals, six years or so ago, it didn't work that way. You would click a journal article, maybe click through a couple of crappy login screens, maybe navigate up and down some menus on some journal's CMS, and finally find the article after a bunch of surfing. It would have footnotes. The footnotes were almost never links. Instead you had to manually type their key information into your local library's website in some other window, and then hope that your local library had the journal, then surf through some more screens and up and down some more delightful CMS cruft before you found the article.

Smart folks would download PDFs of everything as they went and then file them in some personal database like Endnote. But they still wouldn't be cross-linked. You had to spend time organizing them, or use the search a lot.

I assume that this workflow has improved at least a bit since then. Maybe Endnote or its competitor is smarter, maybe journals have finally started publishing hyperlinks. Maybe it has even improved to the point that academic literature is half as easy to surf as, say, tvtropes.org. In which case I take back much of what I said, and we can go back to estimating how many people can actually be expected to access the blessed terminal where all of this can happen. But I bet it hasn't improved that much. I bet it's still impossible to construct a hyperlink from Nature directly to Science, mostly because they've got different and incompatible DRM.

Mind you, things are heaven compared to when I was in grad school, when following references from a paper meant going into the stacks, laboriously collecting one heavy paper volume per footnote, physically hauling them back to a photocopier, and copying the articles two pages at a time. Oh, the hours I spent. Life is much better now. But, you know, young people don't know or care about how hard I had it. All they can see is that it's fifty times easier to research the plot of any episode of Neon Genesis Evangelion than it is to follow a chain of citations from a Nobel-winning publication back two generations, and that a popular article about a videogame from 1980 can link to its sources but a popular article about a publication from last Wednesday's Nature can only link to a paywall.

Science is always going to be a hard sell compared to the rest of our culture, so why do we make it even harder?