This decision goes way above Tony Kerns paygrade. People are using him as a scapegoat and suspicious he wants to just have the mil do the tanker side, since he is ex-AF, but I dont think this is about him.
This is more about a USDA/USFS culture that is less about getting the job done, and more about how can we lessen personal risk and our own liability (our own as in those at the top). They are worried than can be personally sued, if an large airtanker has another structural failure.
Everyone agrees newer planes will be needed soon, but the USFS does not want to pay more, or have longer more stable contract periods, they just barely pay enough to run the current aircraft.
The tanker industry is probably now safer than it ever has been, and the planes have been inspected deeper then probably since they left the factory. The captain I flew with told me they had FAR more crashes and structural failures in the past than now.
They even know more about why those 3 failures in the past 10 years have happened, and what to do about it, and how to prevent it in the future.