Samsung had existing repair partnerships. Many were run by other Koreans, and very much had the feeling of a big family run conglomerate. Of course iFixit is going to get the short end of the stick unless they're providing real value to Samsung.

For Samsung, repair services are valuable to keep carrier customers happy so that the carriers keep pushing their phones. External repair services don't have that tie in. They probably even reduce sales of new phones. iFixit's partnership just doesn't offer the same value proposition.