It should not happen that the way of people should become like one when one could be erased from the history at any given time from the society. It is quite true that most of the families in Oceania are quite falser and more inexpressive than the other families. They are not expressive to their own family and they tend to give up their own family members for the sake of the party.
This is not how the families are supposed to be in any society. But, a huge amount of people does not trust and believe in the form of society which is quite strict and has absolute control. The domino line would come into effect if enough families were border upon the Parsons family. Orwell tries to make an attempt to warn the people about the fact that the destruction of families in any of the society is dangerous through his book. The government if allowed to continue would continue to have way too much of control over the mindless society which could be turned into any way the ruling class chooses to.