There have been a lot of tributes to Casey Kasem in the wake of his death, but, really, they ignore the fact that he was not a beloved figure within his own radio community.
This outtake was leaked specifically because it was hilarious and showed the real man. He goes ballistic in the studio, yelling at his staffers, and they leaked it because he was a dick, plain and simple.
What will endure for Kasem is the voice work he did for animated shows. He will forever be the voice of Shaggy from the Scooby Doo cartoons, but no one will remember the various Top 40 programs in any substantive way. He was responsible for killing the franchise he created by leaving the program over money and then creating a rival show with the same format.
It was formula broadcasting--the host would record intros and bumpers and filler and then engineers would use the full three hour block to inject songs into the program wherever there weren't commercials. Radio stations were issued this program on vinyl records for decades, and I remember spinning them. The manner in which it airs now is irrelevant largely because it is in the hands of Ryan Seacrest and, because of that, it's all but dead in terms of cultural significance.
It was filler, and nothing more. Radio hosts like Kasem have gone the way of Arthur Godfrey.
I know. Who?