I believe their idea was to increase ratings. They didn't understand their audience...over 65, doesn't follow the issues too closely, Democrat, doesn't like to change show preferences too often, comfort.
Everyone else is gone and ain't coming back. Unless they get a Brit Hume or different point of view to get NEW demographics, they will be stuck with the same ratings over the three channels. The puff pieces were good for train-wreck-watchers, but they already saw the wreckage.
Network news will be on the ash heap of history within a few years anyway. It's a money loser, since the all-news Cable channels are where people go to now.