In their heyday the Pet Shop Boys were the Interpol of the Eighties dressing up to sing really weird pop songs about lust and loneliness in the big city. They're low-pro now not retro-worshipped in the manner of Depeche Mode New Order or The Cure but you can hear the reason why - these guys are too sad.
In some sort of crude sense which no vulgarity no humor no overstatement can quite extinguish the physicists have known sin and this is a knowledge which they cannot lose.