Before we backslap too much, note that the study isn't about programming skills, it is about sitting on SO all day answering questions instead of working.
That would be a more compelling argument if the startup community hadn't spent the last several years claiming that participation in online forums like StackOverflow is a good metric for evaluating the quality of potential hires.
Exactly. And lately, it seems to Github repos and open source projects you've contributed to (which actually isn't so horrible).