What you actually said is ridiculous:
"Your (and the sibling) responses also beg the question: must governments contract to big foreign consultancies? It's not illegal to do things in-house if they so choose, you know."
No, they don't must do this. No, it's obviously not illegal to do things in-house. They choose not to because it's obscenely hard to build what Palantir has already built and to battle test its security anything close to what Palantir has done.
(Disclaimer: I used to work there, so you can go ahead and dismiss my opinion outright, but I am responding directly to what you're saying)