> And how many of those people then proceed to type those links into their web browsers, shortened or not?

That probably depends on the link's purpose.

"The full dataset and source code to reproduce this research can be downloaded at <url>" might be deeply interesting to someone in a few years.

So he has a computer and can click.

In any case a paper should not rely on an ephemeral resource like internet links.

Have you ever tried to navigate to the errata corrige of computer science books? It's one single book, with one single link, and it's dead anyway.

I’m unconvinced the researchers acted irresponsibly. If anything, a Google-shortened link looks—at first glance—more reliable than a PDF hosted god knows where.

There are always dependencies in citations. Unless a paper comes with its citations embedded, splitting hairs between why one untrustworthy provider is more untrustworthy than another is silly.

The Google shortened link just redirects you to the PDF hosted god knows where...