I have to say that while your approach to responsive web applications makes sense, it is geared toward bigger web applications. The users of the application I'm currently building need to see everything on all platforms they use, the information just needs to be displayed in a different manner. The app is also small enough that loading something only to then hide it with a media query is not really an issue. It's obvious that building bigger apps you need to take conditional loading into account, but I'm not sure where the tipping point (in terms of app size) for that is. It's also true that the tipping point is moving as mobile internet speed and general performance increases.