Sadako said:

In all seriousness, though it was an interesting technique. It's reminiscent of voice acting work--VAs aren't in the same room, delivering their character's lines to each other. They deliver them to the sound booth, and then the director tells them how wrong they did it, and makes them do it again, but this time angrier. Then the best takes are edited together, ba-da-bing. It's part of the expectation among voice actors, but not for live film actors because it's an entirely different set of skills (not unlike the difference between film and stage, or stage and opera).

All of the best productions make sure to have their cast record at the same time. Ask any voice actor and they'll tell you group sessions are the best. It's a shame they're the exception and not the norm.