Social exchange theory maintains that it is the valuation of each relationship's benefits and costs that determine whether we choose to continue a social association or not.This theory, founded by sociologist George Homans, suggests that people compare the possible benefits and risks of social relationships and based on it If the risks outweigh the rewards, people r give up that relationship.
Well some people just don't agree with their ways and also some people were born into family's that just don't like people like that I hope this helped