He was invited into the living rooms of millions of Americans and reported the news. Unlike today's biased networks who purposely leave out all the facts and all the information, Cronkite would tell you what he knew.
Consider the clip below.
Clearly shaken by the sudden death of JFK, you can hear a crack in his voice. A crack that signified that he, like the rest of the world, was effected by the news of Kennedy's death. You can see it in the video at about the 5:15-5:20 mark. Cronkite's professionalism soon takes over and he reports the news as he knows it to be.
And that's the way it is.