I went though most of the tute and I made an app where all the logic is done client side. I am not using any executable files like aspx or cfm or php. Everything is done client side with AJAX calls to a REST web service. The only thing that is done server side is a controller and a single class to define the data structure AKA the Model. All the controller does is intercept JSON from the AJAX calls and updates the database via an ORM. There is no SQL, The entire thing is done via a couple static html pages. It looks nothing like a traditional web application where the server dishes up rendered HTML files. In fact, since REST is standardized and is supported by all web app languages it is utterly irreverent what is going on server side. I could swap it out to work with CF, Rails, PHP, Java or whatever. One of the cool things about CF (you knew it was coming) is that JSON is a return type for functions. You can run a query and the return value (the query) is automatically turned into JSON with no intermediate steps.
But yeah.... everything I know about web dev is wrong. Again.
My point? JabbaTheScript is THE language to learn. It is the single most important language of our day and age. Logic is moving from the server to the browser. The back end is quickly becoming little more than a service layer for your database and for things that JS and/or mobile apps can't do or do well. I have heard several times in the last week (from developers of various back end languages) that the back end is "just a matter of preference anymore". Everything is moving to AJAX, Mobile apps and client side app MVC frameworks like Backbone.js and Angular.js so just as long as you can expose your back end via Rest and/or SOAP web services it really doesn't matter what you are running server side.