The first season of Big Brother, for example, was rather dull, with the contestants sitting around, not doing much. The excitement came from viewers trying to send messages to the cast via aerial banners, adding a little bit of chaos to the otherwise ho-hum proceedings. The show had to add controlled dramatics by inserting "Head of Household" and "Power of Veto" competitions, as well as other contrived elements like a saboteur. Now, the twists of the show are actually expected by both the audience and the players.
Survivor popularized many of the elements of reality competitions that have now become common place, such as the villain who masterminds an alliance and backstabs his or her way to victory at any cost. Survivor has survived for over twenty seasons (averaging about two a year), but it too has had to add new aspects to its format, like the Immunity Idol. While it would be interesting to just drop contestants in a wildnerness and have them hunt for food and search for shelter using nothing but their natural physical and mental attributes, the producers could not take a chance with true reality -- we would have had long stretches of nothing happening, and then moments of terror as contestants risked life and limb. They had to give the show reliable, consistant structure similar to fiction by adding challenges, sparking contrived drama through editing that implied romance, rivalries, and danger, even when such things might not actually exist.
Documentary movie makers have long taken real people and real events and added some emotion through editing choices. It has been happening since Nanook of the North. Television documentaries are no different, from the early pioneering shows like Candid Camera, An American Family, The Real World, and Cops, to the modern shows that have continued the reality genre format: American Idol, Hell's Kitchen, The Apprentice, The Amazing Race, and on and on.
Like it or not, reality television has been so successful that it has its own familiar ground rules, tropes, and character types. If a new innovative element appears on one of these realilty shows, rest assured that it will be copied to death and added to the long list of cliches.