MTV, from the moment it first began, has been dominated by absolute utter wankers for interviewers. Look at Tim Kash's interviews with Amy throughout her career for an key example of this.
As for this interview in particular, from 4:18 to 4:40, when she was ambushed with the question about the drinking. Like who the fuck does that, what sort of decent interviewer would do something like that? Have a conversation with somebody, don't just bombard them with questions that have a sting in the tail. Even the guy towards the end who spoke of people wanting to have a connection with her because of the music - what is she supposed to say to that? I mean I understand the relationship between an artist and their audience shouldn't be solely transactional, but at the same time there's bounds of reason as to how much your admiration for someone can go before it gets sort of awkward, especially when you're face-to-face with that artist.
I don't know, this whole interview has always struck me as being just really icky and fake. The only person who actually spoke to her on a human to human level was, as you say, the black interviewer. Maybe if more people/media outlets did that then she wouldn't have been criticised for being hostile, I'm not sure.