I think this sort of self-perpetuating bureaucracy bloat has characterized most post-war weapons development in the Pentagon. The F-16 was an exception and success from what I understand, because of what another poster above refers to as spec management (I presume). i.e. it had a small group of proponents who had both extensive pilot experience and also the engineering/management chops to understand clearly what they wanted aeronautically, and were good at running a "rebel" program within the giant DoD bureaucracy to keep that project coherent and focused...until the very end when it did pick up a bit of bloat when it necessarily was exposed to other parts of the DoD.

I think in order to be successful, they probably have to implement some sort of "small teams" approach; I'd imagine a lot of tech developed for JSF/F-35 can be rapidly rolled into a 5th gen+ fighter without reinventing the wheel...but they'd need to firewall the project into small focused teams who really know what they'd want to build.