The surviving film footage and documents help with the holocaust's standing. I'm sure that had we footage of medieval England telling jews to stand there in the tidal flats and wait for boats to come pick them up (of course they meant that high tide was on the way to drown them) we would find it equally creepy. The acts themselves are morally equal in each instance despite efficiency. But as stated, things like efficiency lead people to perceptions of being more cold blooded etc.