To a sister who admires Muslim families and societies: This is because previous religions were oriented towards personal development(tazkiya) or at most tribal supremacy(asabiyyah) while Islam also includes social engineering through focus on congregation(jamat).
Peter Bell This is a fine thing wherever it is consistently true in practice. Of course, tazkiya and jamat go together and reinforce each other — overemphasis on either one produces a society (and individuals) in imbalance and disorder. But your description here is accurate in that it is quite possible for a religious group to focus on the individual development and fall short of the logical progression of the tazkiya into jamat. Fully functioning jamat will not happen unless the individuals are spiritually strong and healthy.