"U.S. officials say a key driver behind this decision is a fear that America’s industrial base cannot develop and produce two different advanced stealth fighters simultaneously."
So its official. They acknowledge that their industrial base may not be able to match that of their greatest rival, and so have pragmatically chosen to focus on a single 6th-gen fighter project rather than try two and fail at both.
The only headscratcher is why they've decided to focus on the USAF fighter and not the USN plane. America's lack of strategic depth in WESTPAC means that even if they had the best land-based fighter in the world, it would be hard-pressed to fight without safe bases where it can launch with combat loads. Having their only 6th-gen fighter be the Navy's carrier-borne mainstay makes sense, it being essentially an F-22 replacement that also cannot fight over the Pacific does not. Unless they really believe the F-47 will have revolutionary improvements in combat radius?