I found “Big Bird” being used as the byname of public broad services in the article titled,“The Red and Blue Fantasies behind the Big Bird War” appearing in Time magazine’s October 9 issue which begins with the following sentence:
"There is a reason conservative’s dream of cutting funding for Big Bird, but it has nothing to do with Sesame Street. Behind the big yellow fowl is a fantasy: the idea that the federal budget can be balanced by doing away with wasteful ephemera that no one really needs. “I like PBS. I love Big Bird. I actually like you too,” Romney said at the first debate to Jim Lehrer, the moderator. “But I’m not gonna keep on spending money on things to borrow money from China to pay for it.”
From the context of the above sentence, I surmise that Big Bird appearing in the popular children’s TV show, “Sesame Street” became the nickname of PBS. If I am right, I wonder why just one of 1,000 Sesame Street characters comes to represent for PBS.
Why PBS is called "Big Bird"? The article says “There is a reason conservative’s dream of cutting funding for Big Bird, but it has nothing to do with Sesame Street.”
Why don’t you say simply “PBS,” which I think is short enough word that doesn’t need to take a bother of inventing an alias?