I know how it works, Gripen saw the same debate.
The difference now is that u guys have put all your eggs in the same basket, F-16 was intended as a day time fighter from the very beginning. F-35 is intended to replace pretty much everything from Hornets to Warthogs and Harriers. If the F-35 are unable to fulfill all these rolls it can have serious impact on the US military capacity. The teen fighters are getting older and older and the F-35 dont have too much time left before it have to start replacing the older airframes.
And there are a lot of other countries involved, countries that are less resistant to increased cost than the US. To European countries there are alternatives like EF, Gripen and Rafale. If the cost for F-35 goes too high there are a risk that European customers will choose another aircraft and leave US taxpayers with an even higher burden.