I’ve been using Joomla for about 2 years, including extension development, but now I’m thinking on going a step further and either start with Drupal, or learning some PHP framework (CodeIgniter seems the most appealing after watching some video tuts).
I know the difference of both sides. Framework: a skeleton with classes and design patterns to help you build any website much faster than from scratch, CMS: an application built with its own framework which a priori is aimed at content management (articles/items).
From my experience in Joomla, you can currently code almost any extension you want, not only for content management. So what I’d like to know is whether learning a bare framework is worth it. Someone could tell me something you could do with a framework that Drupal/Joomla couldn’t?