And once you remove the friction for requiring cryptographic verification of each component, all it takes is one well-resourced lobby to pass a law either banning user-controlled signing keys outright or relegating them to second-class status. All governments share broadly similar tendencies; the EU and UK govts have always coveted central control over user devices.
As said above, it's about who controls the keys. It's either building your own castle or having to live with the Ultimate TiVo.
We'll see.