Last November was the Presidential election. It's not surprising viewership is down. FNC's relatively better numbers just indicate the frustration of liberals and their lack of interest in watching Obama implode.
Perhaps you didn't read the article,but the article indeed made it clear that a certain bleed from election year highs was expected, but this was dramatically outside the norm. As to the idea of watching Obama implode…I think that is why they are tuned out and what is significant about the entire story. To me, that Obama is imploding is more important per se than these cable outlets.