It's not just limited to the F-35 program. The Air Force has been looking for a one size fits all fighter since the late 50's. The Perfumed Princes seem to think that it will simplify logistics and maintenance, but what it's really about is consolidating the last of the defense contractors into one entity for maximized profit. I submit the F-111 as a prime example, and Robert S. McNamara and his RAND Corp "whiz kids" first proffered the idea.
Dude smells like a SAS sheep dip.