God does say to be fruitful. However, living a life of celibacy is greater than the procreative life. Not to diminish the married life, but celibacy is considered greater. Also, not everyone can have children due to genetics or other issues. I understand your sentiment though. Westerners no longer have children and this is by the devil's design. Instead they frustrate the natural end of the conjugal act that goes against nature and that includes married couples as well.