I'm a high school computer science teacher, and I use CodeCademy in my intro Web Development course.

For my use case, it's not bad, but the students are working through the lessons in class with me there to help them when they get stuck. And they get stuck a LOT. The lessons are improving (slowly!), but they've still got a LONG way to go.

I can't imagine anyone is teaching themselves to code anything using CodeCademy that couldn't have done just as well using a tutorial online. Anyone with the natural aptitude to make it through their lessons could teach themselves with damn near anything.