There's a big difference. I enjoyed Sagan's TV series when it came out (see how old I am!). I think I would still enjoy it. I enjoy National Geographic. I enjoy other pop magazines. But there's a big difference between these, and books like ABHT. These things are about *actual science*. Things that specialists found out, and which are now explained to the public, in easy-to-understand language. But they are NOT about totally speculative dreams of theorists. I find it enlightening to learn some actual science stuff outside of my field of expertise, be it paleology, planetary exploration, oceanography or whatever. It is REAL STUFF. ABHT is speculative. What's the point in trying to tell non-specialists about what half-baked ideas you have that you didn't succeed in completely working out, but what they are overly enthousiastic about ?
Carl Sagan's enthousiasm was of a different kind. It was more of "look what we've understood already!".
Another brilliant pop book I still like a lot is "the first three minutes". It's of the same kind.
But the "look how bright I am, I think of stuff nobody else thinks about, only, I don't know yet how it all fits together, but I'm so smart that I'm enthousiastic that I'm going to find that out one day or another" kind of books annoy me. Probably because I feel cheated, and that at some point I believed all that, just to find out (when I learned more about it) that things are not that simple.