The idea behind some people leaving was that the Daily Planet would probably mean more to some people than others. (Skip never thought it was an impotant enough job, for example.)
As for the amount of people who are actively particapating in the investigation, I went by the people who particapated in the "What happened with the Daily Planet" in House of Luthor. Even though they were all upset, only Perry, Jimmy, Jack and Clark investigated it.
I figured there would be a level. Those who don't care at all because it was "just a job."
Those who care but are more concerned about money for various reasons so they have to look for another job, and those who will stick by the Planet no matter what because it's "like family."
