voted off (your secondary characters)

Last night (Wednesday's night) to the shock of many Alexis Graces was voted off season 8 of American Idol. Ryan say at the beginning of every show "Anything can happen" and last night it did.

Now how to transport this into a lesson on how to write... Well I don't know about other writers, but I always have to many secondary characters in my story. People tell me all the time that my stories are confusing because the reader can't tell who talking or doing what.
So I have to "vote off" my secondary characters. I have to look at their performance to decide who stay and who goes.
Are they written well?
Are the a "whole person" or a "stick drawing person"? What i mean are they well developed or are they flat on the page like a stick drawing a child does.
And most important Do they move the story a long?

Dear Reader,
Do you think the judges and the people who called in made the wrong decision by letting Alexis go? Also what do you think of secondary characters you come across in books, TV shows and movies. And writers what do you do about your secondary characters?