I like being able to change the behavior of my application without having to make changes in the markup (some of which can even ripple out into the stylesheets)

I like being able to change the behavior of my application without having to make changes in the markup (some of which can even ripple out into the stylesheets). Things just scale more cleanly as the app's complexity increases, and the separation of concerns feels much more productive than having to search through hundreds of lines of HTML for in-lined function calls.