The author echoes many of the same reasons I really dived into Node - I'm a strong C# back-end developer but really hadn't had much experience designing web UI (HTML5/CSS/JS.)
I can say without a doubt that my experience with Node has translated to some upside in terms of my front-end JavaScript abilities - being able to really master the ins and outs of JavaScript language itself has made it much easier for me to work with even some pretty nasty front-end bits.
In addition, you pick up a lot of tools in Node that are translatable to client-side JS development. Many of the unit testing frameworks work just as well at testing client-side code as they do server-side.
I can say without a doubt that my experience with Node has translated to some upside in terms of my front-end JavaScript abilities - being able to really master the ins and outs of JavaScript language itself has made it much easier for me to work with even some pretty nasty front-end bits.
In addition, you pick up a lot of tools in Node that are translatable to client-side JS development. Many of the unit testing frameworks work just as well at testing client-side code as they do server-side.