This may or may not be true, but you don't have to manipulate the result if you control what people see on the way there. One thing is certain. The producers want ratings. They are not journalists producing a documentary, trying to give the most accurate representation of the events on the island. They want fans, and ratings.
TV producers know how to make a compelling story, even when working with unscripted material.
The ideal story involves drama, heated competition, and victory by an underdog. If the probable winner becomes obvious, they don't want you to see that any more than they want a 42-7 SuperBowl. Unlike the SuperBowl, they don't show you the whole game. Dramatic, and more than a little bit unexpected. Make it a drama of good and evil, back and forth.