I think a difficulty with science communication is that it is very rare to have someone who is both a great scientist and great science communicator, and even with the ability, it is difficult for them to devote enough time and focus to be great at both. Feynman was, if flawed in some ways as a communicator. Hawking was, but I got the sense that at some point later in his life his focus on communication to the public limited his ability to continue doing research rigorously (after somewhat idolizing him as a child, as a graduate student I went to a research talk he gave to the theory side of our department, possibly in the context of TAPIR, that was both embarrassing and depressing, as it both felt like he really wanted to keep doing good research and very clearly couldn't manage to, and it seemed like everyone in the room knew it, including him). Einstein, despite having the ability to draw a public audience, arguably wasn't a great communicator.
On the other side, while yes, NDT is problematic, I think there is a value to people who are great science communicators without being great scientists. Sagan was arguably a great science communicator and not a great scientist per se. But his communication to the public was inspiring and educational, with enough rigor but not too much complexity, with a sense of wonder but not too far into speculation presented as science, with intuitive explanations but without too disastrously overburdened metaphors. There's the view that his talent for communication and broad intuitive understanding was such that even his contributions to research came primarily from his ability to be, in Kuiper's words about him, a "liaison between sciences". But even when just to the public, someone devoted to that sort of work, and good at it, is not less valuable than a scientist.
