My understanding is that guests can insist that certain things not be asked about in interviews, so Barbara's questions were preapproved. I didn't see the episode, but with the drug/alcohol problems that Bobbi Christina has it seems odd to not address it. I think too many people tap danced around her substance abuse problem and it ended up killing her. Whitnes has been dead for a number of months. I'm not sure how addressing Bobbi Christina's substance abuse at this time is rude, inappropriate or irrelevant. Perhaps facing the truth could save her life.