This is true in many cultures, not just Arab or Middle Eastern ones. This is done in the different peoples and cultures all over sub-Saharan Africa and Asia. Many Eastern cultures have a stronger sense of communal unity - the family is the most paramount social structure.
For example, parents and children living together even when they grow up is not only common, it is considered an honour.
Hence, "preserving" those familial ties is honourable in many cultures.
