Wouldn't surprise me if that's how she got to where she is today.
The past few times I've seen her on TV, she has appeared to be drunk or high on some drug. Or maybe she just doesn't know how to act around people not from her native environment, which I assume is the upper west side of Manhattan. Whatever the reason, she's come across lately on TV as pretty strange IMO.
Diane Sawyer “worked” her way to the top by, shall we say, “handling things” for the decrepit, senile, 80-year-old William Paley, then pres of CBS news. She was, and remains, shameless.