I'm not sure what your experience is with kids of high school age, but in my experience (around 10 years of teaching high school CS) it's very rare to find kids

I'm not sure what your experience is with kids of high school age, but in my experience (around 10 years of teaching high school CS) it's very rare to find kids who are capable of jumping into a complex environment and learning much from it. The vast majority, whilst they are interested in writing games or mobile apps etc get discouraged by the weight of new concepts and just tune out unless they get spoon fed everything. Back when Flash was more in favour I used to do ActionScript programming with my 15 year olds as a basic course since it was relatively easy to wrap your head around building something to look at and then attach code to it (one of the few redeeming features of Visual Basic) and even then few kids coped well. I've yet to see much success from high schools I've visited that tout courses that involve mobile development and what have you that don't also have very large pools of students and significant streaming of those kids into the CS course. Now it could be quite valid to argue that perhaps I'm just not good enough at teaching, but I've seen enough top end success with my students that I don't think that's enough to explain it away.