Earlier quoted context omitted.
Not the argument you're looking for, but I've been playing drums for over ten years now because of Rock Band. Even used the sticks that came with it on my first e-kit. The game didn't teach me how to drum, but it taught me that I had a much deeper interest in playing drums than I'd ever imagined. That led into years and years of practice and I've actually become pretty good.
And that scenario is covered in the post, in the seventh paragraph. Nowhere in it is Scalzi saying Guitar Hero can’t give you an interest to pick up the Guitar, quite the opposite . The point being made is that when you do pick up the Guitar, you’re starting to learn from scratch, your years of playing Guitar Hero don’t really give you a head-start.
Sure, it’s all gamified and fun and even addictive, but at the end of the day no outside, transferable skill accrues to the player. To do that, you have to set the controller down, pick up an actual guitar, and start another, entirely different journey. And perhaps some Guitar Hero player did or will, which is awesome. It means at some point they were not satisfied with pretending to play the guitar, following someone else’s rules and set-up. They still started, effectively, at zero. There was a whole new skill tree to be learned that had very little to do with the game, outside of the shape of the controller.