Good questions. On the Secret Service, etc, they are not political appointees. They don't accept an assignment from the president specifically to represent his views to the public.

The Forbes editor is addressing his magazine's "moral / ethical community"—the business world, particularly the world of corporate communications/messaging—and saying very clearly that hiring someone who accepted a commission from this president to literally lie on the regular to the public would be beyond the pale.

The Forbes editor addresses that chunk of society that his magazine reaches. Society and culture isn't a monolith; we all have micro-communities to which we belong, and we collectively influence the standards and norms of those communities. So if someone in the defense industry wants to take a stand re: not hiring some of Trump's underqualified and questionably committed "acting directors" of various branches of the defense/intelligence apparatus, they'll have to take that stand and see if the industry will follow their lead.

I have absolutely zero doubt that every single member of the Trump administration who wants a job will be able to find one after January 20. None of them will be without a source of income. What they will be without—and, in my view, what they should be without—is broad social respectability. There are communities of political thought that will laud them as heroes and pay them accordingly. But they will be booed in restaurants for the rest of their lives, and if that is the price society exacts for the practice of telling lies that built up to an assault on the US Capitol on January 6, then they should be grateful the consequences are so minimal.