Because it's not just a science thing. It's a potential threat. Threat is defined as capability x intent. We are seeing these things with insane capabilities, but not really any intent (other than maybe observing our technology).
The former Deputy Secretary of Defense for Intelligence wrote a blog alleging that there are black projects hidden within DoD contractors that are reverse engineering non-human intelligence craft. He's presented enough evidence to congress for them to add specific legislation to bring these programs to light.