Good point Sunrise.
My husband, though, is an extremely avoidant guy in general, but particularly and most painfully toward his family. His dad kinda dropped contact when my H was 14, and although my H's paternal grandmother has tried to contact H, the letter is still sitting on his desk unopened after 2 years. He only talks to his mother about once every 6 months, despite her sad phone messages at least every two weeks. Same with his maternal grandparents - his grandmother had a major medical problem which kept her hospitalized for over a month, and not once would he agree to call his grandfather to offer some support.
I'm not particularly close to my family either, but I find my H's avoidance of his family to be bizarre. I can understand holding resentment toward his dad, but it's flat-out refusal to maintain communication with the rest of his family for reasons he hasn't articulated. I feel really bad for them - it has to hurt