2. It seems a tiny bit optimistic to expect a malicious government to abide by copyright law.
I think the goal of making this open-source is to enable third-party review to avoid innocent mistakes, not to allow you to audit that the code hasn't been maliciously and intentionally modified. There isn't a great way to audit that the binary you download from the App Store matches specific source, for instance.
Many large, public (as in publicly-traded) companies also have an aversion to GPL. Most enterprises that have a technology review board or legal review of software dependencies (aka any regulated industry) have a dislike for GPL in customer-facing services.
And no, "most" enterprises aren't averse to GPL code for usage. They certainly will have policies about making their own software depend on it, but that's different from simply using it, which was the original topic here.
For example: https://github.com/OpenSC/OpenSC/issues/1992