It isn't the full explanation, but when they go all in on this every few weeks I'm reminded of
this Pareene piece.
Yeah, there are guys (and it is guys, for the most part) out there who spend their whole careers trying to be Dan Rather staring down Nixon or Cronkite turning on Vietnam—or even just Tim Russert making some elected mediocrity stammer with a patented “tough question”—but mostly these guys want to be witnesses to Great Men Making History. They want to Respect The Office Of The Presidency.