Ah OK, thanks - that's good context to have. So I guess some of criticism here on taking someone from the defence industry has more substance to it than has been suggested.
This all emanates from a problem that goes beyond just the defense industry and beyond just the US, despite being quite pronounced in the US. Which is that there is a gap in the prestige-to-pay ratio (I'm making up the term a bit but have read about the concept elsewhere) of the public sector vs private.
So if we look as Lloyd Austin as an example, as a 4-star General he had very high prestige and power. He spoke on behalf of the United States and the US Army on a daily basis. He had thousands of personnel whom he would direct, and probably also a considerable personal entourage to help him do his daily job. Whenever he was in a room, if the Secretary of the Army, Secretary of Defense, the Chairman of JCS, or the President himself wasn't there, he was probably the most important person in that room (there's other people more important than him in govt but don't want to get exhaustive). But meanwhile his bank account only saw some $200K annually, minus tax. That's by no means poor, but its also what an Investment Banker 3 years out of college might make, and its a fraction of what even someone in charge of any division at a Raytheon makes (not that he was a division head at Raytheon, just an intra-industry comparison).
This situation is the same at virtually every equivalent post in government. A US Attorney for SDNY can investigate and take down a global football corruption scheme, organizing arrests to happen simultaneously in numerous countries around the world. But they make as much or less than a 2nd year lawyer at a white shoe firm makes. When these people leave government they are almost immediately tempted by offers to make in just a few years what they made in the public sector for decades. They are often both competent, which is why they rose to the top of their fields in govt, and have very high prestige in their field. Companies are willing to throw millions of dollars at them depending on the role, and the companies figure its a good deal.
So the question is what to do about it. Just continue with the present regulations that at least force them to sell out of their private sector interests when going back into government service? Prohibiting senior government officials from ever serving in the private sector? But wouldn't you have to increase pay to still see a pool of competent applicants? Increase pay regardless so that private sector works is less attractive in a relative sense? I don't have a firm view on the solution, but I think the problem here another symptom of what I described.