The Cronkite link has this telling excerpt:
"The first night up, he ended the show by saying, I'm paraphrasing, 'That's the news. Be sure to check your local newspapers tomorrow to get all the details on the headlines we are delivering to you.'"
That didn't fly.
"The suits -- as we used to call them -- went crazy," Socolow told CNN, referring to CBS executives. "From their perspective, Cronkite was sending people to read newspapers instead of watching the news. [Emphasis added.] There was a storm."
CBS News President Richard Salant met with Cronkite, who initially resisted, then agreed to change his sign-off, Socolow said.
"In the absence of anything else, he came up with 'That's the way it is.'"
Oh, the horror! People reading newspapers! It's a wonder civilization survived long enough to see the advent of television. (Whether it will survive the advent of television is still an open question.)