The race car/pickup truck analogy is useful here. The F35 failed because they tried to make a vehicle that could be both a race car and a pickup truck, and wound up making one that is more expensive and worse at both jobs than building two different vehicles. Or just using existing fleets of vehicles.

Although personally I think that in the event the US military needs to scramble a bunch of F35s to serve as in legitimate air to air combat we'll have bigger problems than a costly jobs program not producing something useful.