The difference between science journalists and communicators? Journalists don't smile.
One problem is that science journalism and science communication are conflated. Communicators (TV and radio stars like Brian Cox, Jim Al-Khaili and Alice Roberts, for instance) are a friendly conduit between scientists and the public, essentially working on behalf of researchers (and often from within the scientific establishment) to help people understand science better. Journalists are supposed to be more adversarial, interrogating scientists' claims and motives, and any policy responses, with the aim of finding truth and clarity. Sometimes, as the Association of British Science Writers' Connie St Louis has pointed out many times, the press and broadcasters are so busy communicating, they lose the point. We science journalists should be no more on the side of scientists than political journalists are on the side of politicians.
The merry band of science communicators, bloggers and skeptics who cheerlead for science don't always understand that scientific truths are provisional, and that they're only alienating the public by bolstering divisions between science and the rest. When researchers turn out to be wrong (Andrew Wakefield, who started the MMR vaccine controversy, for example), they're dismissed in hindsight as "bad scientists". Well then, how is the public to know who the good ones are? It's easy to think of the scientific method as perfect. It is, after all, the best system we have for understanding the universe. But so long as humans are the ones practising it, it never will be. Scientists do deserve our respect, but they also require us to constantly challenge them. That's my job, and I really do wish it was more valued.