@Mauss Entirely on the money in my view, as well - though, I watch a lot less of non AB tests, so can't really speak authoritatively about that trend - but, from what I've seen the high ball creates chaos - and teams have got to work out how - on balance - to be beneficiaries rather than victims of the chaos.
I think the Boks have a headstart because they've probably got the strongest scrum in world rugby. It was disturbing to me to see how badly they took our scrum apart - I haven't seen anyone else manage that, but I was also surprised how well the Scots stood up last weekend.
But, back to the Boks - their scrum gives a significant advantage where any ball is knocked on. And I think it encourages their contesters to be more disruptive - as compared to our guys who still very much look like they're mainly trying to catch the ball - which looks cool when it comes off, but might be a lower percentage option. But, also I suspect we're more inclined than most to use the ball in hand in offensive areas - rather than box kick - and on defense we're often kicking for touch rather than to contest.