"Despite it all, Katie still pulls in 6 million viewers a night. Who ARE these 6 million???"
I bet a chunk of it is people who just watch the local CBS affiliate all day and leave the TV on as background music when they aren't watching it. They don't bother to turn the channel when the news they aren't watching comes on.
The same people who watched Schieffer and Rather and before that, Uncle Walter. My guess is that the majority are closer to their age than to hers. But the whole concept of the evening news is so outmoded.