Thank you. Actually this list is made by a genius called Kyle
Chandler.
It tries to win on turn 1 by having 4 mana to cast
Undercity Informer or
Balustrade Spy. This combo only works without having a single land in the deck. So the reason why you generate mana by sacrificing your stuff or exiling cards from your hand is: you need to go off as fast as possible to assure, that the opponent isn't able do that much against it. So for this particular deck Mr.
Chandler avoids manasources that don't generate mana in the same turn they came into play. A huge loss of value in favor of tempo. :-)