"The only say I have is about Ryan [Seacrest], Randy [Jackson] and Paula [Abdul]. I've always made it clear that I wouldn't like to do the show without them. I would fight for any of them," Cowell toldTV Guide magazine in an interview released Monday.
Cowell added DioGuardi is in a "difficult position" because she only signed-on as Idol's fourth judge last summer and is getting her first taste of the show during its currently airing eighth season.
"It's like we friends had dinner with each other for eight years, and now somebody new has joined the dinner table. I think she's beginning to understand she doesn't have to take it quite as seriously as she thought," he told TV Guide.
"If you really want to get technical on this show, I'll find you four of the best vocal coaches in the world, and we'll just hold up signs like you do on an ice-skating competition: 9.7, 9.3. But that's not what we're on the show for. The show is about having a personal opinion of somebody, rather than saying it's sharp, flat or pitchy. Once she started to learn it's about backing the person as much as the voice, she's had a better time."
Overall, Cowell said he's pleased with the addition of a fourth judge.
"You can't keep making the same show year after year," he told TV Guide. "Not only are we going to get bored, I think the public is going to get bored. So I think change, as long as it's not too radical, is necessary."
In addition to adding a fourth judge, another format twist Idol producers had previously discussed implementing to spice-up the show was providing a more intimate relationship between fans and finalists -- something that Cowell feels hasn't happened.
"Apart from Adam [Lambert], who sets his own agenda, I don't think there's anything I can tell you about any of these people, even after seven weeks," he told TV Guide. "Kris [Allen] is a good example. He's a sweet kid, good-looking. I know he's married because he told us. Other than that, there's not a single thing I could tell you about that boy. Nothing."
Cowell added that with so much focus on the judges, Idol has gotten "a little out of whack" since the show is supposed to be about the contestants.
"As the show has become more successful, there's more protection around them," Cowell told TV Guide, adding he has a voyeuristic idea to fix the problem.
"My idea, which I'd love to do, is to plant secret cameras in the house. And then we'd really hear what they think about one another. I'd like to see them all fighting, screaming, hating each other. I hate seeing a united bunch. Because then what's the point of taking part in a competition? It would be like taking part in the Olympics and holding hands and crossing the finish line together. So when [Matt Giraud] made it through and they were all celebrating, I thought, 'Why are you happy?' They don't mean it."
While Fox and Idol producers had planned on including footage of the finalists in the house they call home during the competition, it has yet to materialize -- something Cowell attributes to "time, more than anything."
"For the first time since we've done the show, two hours before the [April 14] show went on the air, we were told, 'Bit of a problem. We can't talk to all of you," Cowell told TV Guide. "Right, that is a little bit of an issue. It would be like telling some of the singers, 'Can you not sing this week?'"
Cowell added that while DioGuardi's addition has made time a "bit" of a larger issue, her gender is apparently the larger problem.
"You add on a fourth person, bad enough," he told TV Guide. "Now it's a girl, huge problem. Girls do tend to talk a little bit more than guys. Randy's quick, and I don't say too much. But my God, these two! Paula's talking more than ever now."
One format twist that has played itself out during Idol's eighth season was "The Judges' Save" -- which two weeks ago allowed the judges to save Giraud from elimination despite the fact he received the lowest number of home viewer votes.
Cowell said if he could go back in time and use "The Judges' Save" on anyone, it would be first-season finalist Tamyra Gray.
Although Idol seems to be intentionally avoiding addressing it directly, Cowell also said that he didn't expect the fact that rumors about Lambert's sexuality have circulated for months to impact his ongoing front-runner status.
"I think people only get bothered really when they know somebody's hiding something. We've had that in the past!" Cowell told TV Guide with a laugh after his not-so-subtle jab at Clay Aiken, who announced he was gay more than five years after he finished second during Idol's second season.
"We've obviously never had an issue with it, and nor should anybody else. It's a huge step forward for the show. It's just, do you like him as a person, as a singer, full stop."