This to me is the real question. I don't see how you could easily create multiple clients if you're practicing what is preached in the article.

You're really tying your server to the browser at that point so things like CLI clients and mobile clients become painful to write (not impossible but ain't nobody got time for parsing HTML when browsers do a perfectly good job of it, not to mention CSS.).

REST systems are designed for use with "generic" clients. The generic client for REST systems on the WWW is a browser. There is probably one available for your mobile platform.