John admits he was approached about the role, but refused to sign up because of his disdain for TV talent shows.
He tells Britain's Radio Times magazine, "I'm not a fan of talent shows. I probably wouldn't have lasted if I'd gone on one. I was asked to judge American Idol. I couldn't do it because I won't slag (criticize) anyone off. Also I don't want to be on television. It's become boring, a**e-paralyzing brain crippling."
And the singer insists he fears for the young stars who emerge from shows like American Idol, because they have such limited creative input in their own music.
He adds, "It's important they (pop stars) write their own songs so they're not at the mercy of anyone. Songwriters today are pretty awful, which is why everything sounds the same. TV vaults you to superstardom and then you have to back it up, which is hard. (They) are at the mercy of the next song they can get."