One of the real lesson of the JSF is the amount of institutional inertia surrounding it. We were effectively pot committed before they had demo planes to play war games with. They spent 10+ years selling the idea. How do you kill a project like that? There is a certain irony to how the US picks weapons platforms too, everybody wants a new toy so who says "no" when the toy isn't quite up to snuff? So politically, we kill all the things the JSF is going to replace, we build love for the new platform, promise the world when nobody has even seen it.
The whole "jump jet" fascination is an interesting one, why do you need to land or take off a fighter/bomber from a place where you can't fuel it, can't reload it, and it doesn't carry cargo and people? Now the concept is cool, I get that, I just don't see where it fits in to the war fighting plan in a general way, not until planes have like nuclear reactors for fuel or something like that. It just doesn't seem generally useful.