How long will reality shows continue to dominate television? I'd guess that, as with prime-time game shows in the late '50s, the popularity of reality shows will continue until a major scandal. I think that someday, a popular reality show will turn out to have been complely rigged -- not just "staged" to a certain extent, as all reality shows are, but planned out and with the winner decided in advance. I think this will happen because the need to keep viewers tuning in will drive some desperate producer to fix the outcome in favour of a more popular participant, just as Twenty-One did with Charles Van Doren). And if that happens, it might seriously hurt not only that show, but nearly all reality shows. Because - and I know this is a shockingly iconoclastic thing to say - the appeal of reality shows is that they're, well, real. Even if they are "staged" to some extent, with producers encouraging the participants to do this and move here and smile at the camera, we want to believe that the things we see are really happening to real people. If there's ever a reality-show scandal comparable to the game-show scandals, a lot of viewers won't be able to believe that anymore.
What makes reality shows more popular than scripted shows, I think, is that people don't feel embarrassed about getting emotionally involved with them. All TV shows aim to create a degree of emotional involvement, of course, and all successful shows get a large number of people to care about the characters (anyone who thinks SEINFELD was an exception doesn't remember how downright lovable these people came off as being in the early years, before Larry David decided we weren't supposed to love them). But there's a certain stigma attached to caring too much about what happens to fictional characters; you'll often hear people say "It's only a TV show" or "He's not real, he's just a character."
With reality shows, you don't have this problem. Everyone knows that these people are being manipulated by the producers to some degree, but when you come right down to it, these are real people and they're not acting; what you see is actually happening to somebody. That guy Bob who ate a bug is not an actor pretending to be Bob, and pretending to eat a bug; Bob is just who he really is, and eating a bug is something he really did. And that means that viewers don't have to feel abashed about following the proceedings and discussing them as though they're real -- because they are, sort of. If you say "Hey, did you see what the Friends did last night?" at least some people are going to tell you to get a life and stop discussing things that aren't real. But if you say "Did you see what Donald Trump did last night?" it's okay, because Donald Trump is real, and the stigma against fantasy -- against becoming too emotionally involved with made-up stories -- doesn't apply. Reality TV combines the week-to-week storytelling of scripted TV with the rule-bound "reality" of a sporting event; it captures the viewers who feel comfortable with cheering for a football team but not with cheering for made-up people in made-up situations.
So that's why I think a game-show-style scandal could hurt the popularity of reality TV; if people feel that it's all acting, that the outcome is fixed just like in a scripted show, they might enjoy it, but they won't feel the same lack of reticence about becoming emotionally involved with a reality show. The phrase "It's not real, get a life" will start to be used about reality shows.
On the other hand, you can say the same thing about professional wrestling, and it doesn't seem to have much of an effect on wrestling's popularity. So maybe I'm wrong about this. And of course, if reality TV does wind up rocked by scandal, it will still come back, just as game shows came back. And I should add that while I prefer scripted TV, I'm not exactly rooting for the demise of reality TV; I don't think it's displaced scripted TV so much as it filled gaps in the ever-expanding schedule. (Because there are more networks, cable and broadcast, there's probably as much scripted TV as there used to be, or more.) And there's nothing inherently with reality TV. There are some reality shows that have more interesting stories and characters than the average sitcom or drama.