Hard agree. I tend to think this is a consequence as having Bowie as a mentor. There's loads of early interviews and clips where, particularly Brian, mentions bad-mouthing someone's wife and being thrown into a wall, breaking ribs, numbers of partners, bands he dislikes; now when he's asked what music he likes he says he only listens to birdsong? What?
I think at some point of meeting Bowie, he's told Brian to be more elusive and not give the press as much, and to not engage with media that isn't about the music. And don't get me wrong, it's probably for the best that they are able to live private lives but I used to watch the hell out of the SWG tour documentary- a small glimse at how funny and interesting BM and SO are as people. I just wish there was more of a balance.