That's actually exactly how the algorithm is supposed to work. Negative emotions are far more catchy. You see dumb boomer memes constantly, you constantly argue, but you're ENGAGED. Which means you're a juicy user for ad targeting.
Sounds flawed, yes. But what makes you think it can't include whether or not the person is a family member as part of the coefficient calculation? And, what makes you think that the way you interact with your family is indicative of the way others do or don't interact with one or more of theirs?