Yes, I agree. Happy families are the same because the reasons of their happiness aren't really relevant - what matters is that they are happy. Unhappy families, on the other hand, each have a story of their own, different reasons for being unhappy, causes which need a lot of thought and work to fight the consequences. Have you noticed that tragedies are the basis for many novels written by writers other than Tolstoy?
I don't know any happy families. I know families who stay together no matter what happens. That involves lots of patience and forgiveness and the ability to survive mind-numbing boreness. Some people think that is a price they are willing to pay for always having financial and social support.
My family is a bone fide mess. Yet I'm not unhappy with the situation. The rest are though.
That said - I don't have a family, I have a pack. And they fight and fall out like one too.
I suppose regarding Tolstoy, it's possible that it's more likely unhappy families have problems unique to themselves? But then again - most families fall out over jealousy issues, money, greed and so forth.
None of which are far removed from each other.
Tolstoy gave me a headache at school. And he's giving me one now