Let’s not entirely disparage human discernment. After all a dog will greet someone the same, whether they’ve been out helping people all day, or murdering.
JWs have a problem because the affection they show is highly conditional on believing the same things and accepting JW authority structure. But no healthy affection is really completely unconditional, because there are things even those we care about the most could say and do that would weaken or break our affection. It’s just that the kinds of things it would take are very different from the superficial reasons that JWs cast people aside.