We (Medium) use async snippets for the few external scripts we load (KISS and GA) and our JS is deferred to the end of the document. Stylesheets and typekit fonts will block, though, unfortunately.
Why do all links on medium point inwards?
Arguments made by those who don't know better are:
1. To track clicks on outbound links
2. To preserve "pagerank" or some such think.
Neither of these are strong arguments since you can track outbound clicks with G.Analytics or any other analytics service worth using, and outbound links have about zero impact on pagerank of the linking page.
What reason could possibly be so great that you choose to break the web for it?
"break the web" is a little melodramatic though.