Well that's generally the case in other media from what I've seen. I can't think of any group Q&As for video games I've seen though. Not that one on ones ever achieve much.
Really it's just a question of courage. From practically all the gaming press interviews I've seen, (again, except Luke Smith anyway), it's like the press are scared to ever press anything, and never ask any challenging follow ups.
It could be because some viewers find it irritating. There was a pretty big deal made about an interview with Tarantino a few months ago in the UK, the interviewer kept hammering away, rephrasing the same question until Tarantino outright refused to address it. No one in the gaming press I know have nearly the stones to try it.