This was such a shame, because it just didn't need to be said. Demi had already given her opinion, and she shouldn't have added that silly remark on the end.
Although, I do think it needs to be said that, likelihood is, it was more a dig at Simon & Idol than a personal dig at Carrie. We all know how Simon feels about Carrie & how much he loved her performance of Alone on Idol, so I honestly think (and kind of hope) she just said it to ruffle Simon's feathers. Those who watch X Factor regularly know that Demi & Simon are always very 'tit for tat' and outspoken with each other, and unfortunately, I think Demi perhaps opened her mouth without thinking & made an off-the-cuff remark in the spur of the moment that was obviously absurd and ridiculous.
It's just a big shame, because I honestly thought Demi would not stoop to such a level where she's bashing other artists to stay relevant. After all she's been through, I thought she'd have more respect for others than that.