Fantasy has had so many outlets over the last few decades with Star Wars, Narnia, and Tolkien and with comics from Marvel, DC, and several independent stories like Conan, R.I.P.D. and Watchmen.
Science Fiction has had a harder time. It's difficult to make up an entire universe for a time well in the future and then make storylines that fit it. Star Trek has been successful, as had Stargate. Even in these cases, though, there have been small cheats necessary to get there. Star Trek's "Treknology" is infamous for being only loosely based on science. Stargate is based in our timeline, with a single piece of totally unexplained technology to start with and a minimum of technology introduced to the early series. They generally added on as they needed to, same goes with "Atlantis". Foreign cultures were either of inferior technology or almost nothing was shown of their superior toys. It was only with "Universe" that something more detailed was really shown.
It's not that science fiction has a lack of creative persons. Arthur C. Clarke thought of the idea of satellite communications. Isaac Asimov spent an entire career writing about friendly robots. Roddenberry may not have created an entirely new and feasible technology but he had the idea that not only different cultures but different species could get along in a common and mutually beneficial federation.
Still though, every once in a while a new story comes along that is science-based and manages to knock your socks off. In 1968, one of the great moviemakers of the time, Stanley Kubrick, and one of the great science fiction writers of all time, Clarke, got together to make 2001: A Space Odyssey, one of the most moving and difficult movies ever filmed. Before that, Orson Welles used radio to manufacture an alien invasion that sent the entire world into a panic. The story of that famous Time Machine has stayed with our society through the decades, being told and retold several times and in many different ways.
I watched Interstellar already impressed with Nolan's body of work (see a few weeks ago), and his storytelling just as good if not better than I saw in the Batman movies and Inception. In those movies the characters have a vitality and depth that goes beyond being interesting, you understand everything about them.
What made it beautiful science fiction is another key feature of Nolan's movies, his use of fractured time. In the past he has jumped backwards and forwards in time, using flashbacks to tell a continuous story. In this story there are only minimal flashbacks, but he uses some beautiful science fiction to accomplish much the same thing. A black hole, a time-space room. It's rare that a new story comes out, more rare when it comes out fully formed. Imagine an idea like Battlestar Galactica first appearing as it did in its second version. Now try to think of a genius like Arthur C. Clarke adding in the science. That's what Interstellar is, a fully developed and beautifully articulated idea that was accomplished the first time around.