For the same reason why there aren't any intensive courses on Windows, ASP, or GNOME. Because technologies come and go --- nowhere more so than in software --- and those left standing are the ones who grasped the fundamentals of their field, not the ones who blitzed their way through a Node.js hackathon. The former are the innovators, the latter are the guns for hire.
All the things you mention can be hacked in under a week by a motivated student. If your objective is to hack (and that is entirely fine for many purposes), you don't need a traditional college course to do so. In fact, I would argue that is entirely antithetical to the essence of hacking!
If you're a Harvard student, you have an amazing opportunity to learn the truly difficult subjects with some of the best people in the world, the kind of stuff you won't learn in two hours in an online tutorial. Take advantage of that; for everything else there's the internet.