I wonder if it's because vlogging is a newish concept and seems to be super popular with a younger audience. Not to say only kids are viewing it, but I know my daughter and her friends (13yr olds) are obsessed with at least 8 different vloggers. It would be nice to see more vloggers expanding their bookish horizons, but honestly I don't really watch many vlogs anyways. I guess you could consider that if you really want to see more of that, you could always "Be the change you want to see in the world."
Yeah I suppose personal stuff can be a deterrent for some but even if a vlogger wanted to talk about books that weren't Adult "Erotic" but simply adult "Fiction" I'd be interested in it. I never see people talk about authors like Janet Evanovich, Philippa Gregory, or talking about Bio's they read, or discussing authors like Dean Koontz and Dan Brown. I'd like to see more of that.
Still on the fence about vlogging though.
Ha:)