I can't see how anyone could have problem with Mariah Carey.
I really like the addition of Mariah. They needed someone who has been VERY successful but isn't 100% loopy (cough Paula.) When Mariah mentored on Season 7, she was great.
I feel like AI is trying to win an arms race, with these "leaks" of people they've approached to be a judge, against The Voice. They can find quality artists without going crazy.
I've always loved the idea of having Shania Twain on the panel - she was great in her previous stint as a mentor AND as a guest judge, but with Mariah that has blown that idea out of the water.
I really like the idea of a Brad Paisley/Keith Urban, Mariah, Pharrell and another female. I really wanted Lambert (I LOVE the idea of a previous contestant coming back to judge, but my preference would have been Kelly Clarkson) but if you're going to go Male Country Artist plus Male R&B/Hip Hop, you need a female to balance the panel out. (Hopefully this means the end of Randy.)
When Simon left, I thought I was over AI, but when they brought on J-Lo and Steven, I continued watching, even when Steven went into "I can't criticize anyone" mode. I just want them to dish out real criticism and advice, and the one loopy judge to say "you look great tonight. Just fabulous. That's all" since that's how you know they sucked.