I don't understand why you guys get hurted so much by things like this.
First of all, it's true that Mariah can be very shady towards her peers. You celebrated her for this for a whole decade now. Demi spoke the truth, really. And she just defended her good friend Jlo (they are close).
At the end of the day, It's not very different from what you do on a daily basis here. You would do and say anything in order to defend your fave (lol). But you get offended if Demi steps up for her close friends, people that she actually KNOWS personally. I mean.
She should know better and try to avoid this, but I think in the end she should be able to speak her mind out.
I mean, you can log off or avoid what she says if it really piss you off that much :S