There was a lot of logic involved in Kishi's decision to do that. He was thinking about the long-term security of the future generations of his family(he's obviously got enough money to set up his friends and immediate family for life). In other words, he was being very shrewd, and opportunistic with regards to making more money, since his descendants are going to be born with a silver spoon in their mouths, and may be tempted to waste a portion of the money away. Obviously, giving Sasuke and Sakura a daughter, along with the other kids of that generation, milks the franchise even more and nets him even more money. Subsequently, he further secures his family for a greater number of generations than he would otherwise do. So, we can conclude that Kishi has an insatiable appetite for money, and that was clearly the exemplary logic behind his decision. Give the man a medal.
