Geez. The "obtuse defense" again.
A. Children are not adults, and attempting to draw any kind of comparison with how adults in a society deal with each other falls flat on that basis.
B. It is not common to treat dissent in a family by shooting the offender or sending them to prison.
C. In a family, the children grow up and are sent out with the family's blessings to become free and independent. This does not often happen to citizens of a Marxist state, unless they sneak out over armed borders.
I'm sure others here could add their own objections.