Websockets are very different to BSD Sockets (TCP/UDP/etc) though (string messages vs. binary packets/datagrams) - if you're abstracting-away then that means devs are ceding a lot of control over the performance dials (TCP_NODELAY? Nagle?)
The example in the article using a Node.js-based game-server is fine, but what options do people needing to run a Quake-style game server (i.e. a ph-phat binary) have?