The whole premise of Rails is convention over configuration. Build a set of tools optimized for the average application following "best practices". And guess what? Rails is still the best framework for producing the average Web application using 2006 best practices.
Now it's 2013. The average application server starts with Rails, then throws away ERB, routing, form_for, and the entire MVC lifecycle and slaps Ember on top of it. Technology has changed a lot in seven years (mobile, javascript, blah blah blah), and more importantly, it's only getting more client side