That's one of my bugbears. You close one door, say, enforcing the law which says the tackler must release the tackled player, then another one opens to a different iniquity.
Playing illegally in front of the ball, or just taking up space which belongs to opponents, is not new, but it is becoming endemic. Before some players like So'oialo obstructed outrageously but now everybody is doing it and the Pom obstruction job in the video is just a variation of playing in front of the ball.
One of these years the IRB is going to announce a crackdown on this and everybody will say what a good idea it is, but we can see the need for it now.
Don't let this drift referee guys else rugby will take another wrong evolutionary turn - just enforce the law as it is written.