Our obsession with Hollywood is massive, but I think people like Bill Nye, Neil DeGrasse Tyson, and Michio Kaku are wonderful figures to further attention on science and learning. Each of them has a charismatic personality that can compete with the likes of Hollywood. Their science programs and specials on television are getting more and more attention, I hope it keeps going.
Yes, the work of men like this scientist who makes science popular is trying to get peoples attention off of things that do not matter, such as the attention on different celebrities, and get them to focus on things that are of great importance to the future of this world.
The popularization of several scientific figures such as Michio Kaku, Neil deGrasse Tyson, and Bill Nye is more of a response to the trend of anti-intellectualism and pro-religious factions within certain political parties. I do not believe that most people even think about these scientific super stars in the same way they would a Hollywood celebrity. They are seen as leaders in the crusade against the anti-intellectual sentiment that has been built up by the Republican party in the US. They are there to provide a counter-point to those who dispute Climate Change despite overwhelming evidence, those who would ban the teaching of evolution, and those that profess the earth to only be 6,000 years old.
Hollywood celebrities are not totally embedded in America's history because Hollywood itself is a relatively recent development, who developed the "celebrity" system to promote their films. Before that, many scientists and academics were regarded to be celebrities. People like Michio Kaku or Neil Degrasse-Tyson, who are famous for reasons other than being in tabloids or on television, are the last of a dying breed.
Today's popular culture includes science geeks and nerds, thanks in part to shows on the Science Channel and the National Geographic Channel. Plus, the comedy "The Big Bang Theory" is also helping popularize science in the mainstream media. It's not a counter-cultural revolution against lame-brained celebrities like the Kardsahian sisters. Popular science is simply a good way to become interested in something different.