The first command of God – a prime directive – is to be fruitful and multiply. Strict monogamy restricts the obedience to and fulfillment of this command.
Do you know of any perfect or even near perfect fathers? If you do please tell us all about him since I know I am not and I would like to know the secrets of raising children that would never fight with each other or go astray.
However, despite our imperfections, we are commanded to multiply and fill the earth. Having children and lots of them is an act of faithfulness to God and a belief in the future. To arbitrarily limit the number of children we have, say to due to false ideas of holiness, is to live in disobedience to God. This is what the false doctrine of strict monogamy does. It says that a man must not have as many children as he can care and provide for but rather whatever one particular woman can have. That number is further limited by more anti-life attitudes and values that make having more that one or two children unthinkable.
Biblical patriarchy is fully pro-life. It sees having more than one wife as a way to maximize the potential to have children and thus fulfill the command of God given in the garden even before the fall.