I'm not sure what the research on that methodology looks like, but speaking anecdotally as someone who's teaching themself how to write dynamic websites, I find that methodology to be very unengaging. '1+1=2' and 'Hello world' console input may hook a younger mind, but I need to see a bigger picture to know whether or not this is going to amount to anything I might be interested in. I shouldn't have felt like I was willing myself through CodeAcademy at times. My time as an adult is limited, so it's important that educational products like these forge a framework for my creativity (and therefore interest) as quickly as possible.

Learning piano, Norman Monath's 'How to Play Popular Piano in 10 Easy Lessons' did exactly this, whereas a lot of the material I ran into did things the classical way, which was entirely boring.