I think the point is that you might not like them, but you love them. And when it comes down to it, while you might not choose to spend every day with them or go out with them for fun, they're still some of the most important people in your life
Generally, of course
That's not the case with everyone, but appears to be the case for a lot of people who no longer see their parents/brothers/sisters frequently but do meet up at xmas