I don't think the two ways are mutually exclusive... in fact I'd say both are needed. I started out trying to throw up a quick website in Wordpress and Drupal, and found out I couldn't set it up the way I liked. So I taught myself to code with resources including CodeAcademy. Now I can build a site pretty much from scratch, hosted on my own server or GAE.

Without my struggles with CMS or frameworks, I wouldn't have known what to code. But without the likes of Udacity and CA, I wouldn't have known how to code it. But, I can now write a functioning webapp after half a year, while working full time. I doubt that would have happened with just books/tutorials or even a university course.

For what it is, these are great learning tools. I can't fault them for not being designed to make you into a full stack developer, yet.

Though I still couldn't have done it without StackOverflow :)