God created humanity for the same reason that he created all things, which is to display his glory. Some glorify God by being saved while others glorify God through judgment. God Himself is the definition of good. Goodness is not a category outside of God. Therefore, it would actually be wrong for God to care for something more than His glory. In addition, God's care for His glory is tri-une. It is based in the Father's love for the Son and the Son's love for the Father so His concern for His glory is based in triune love. All this is explained in order to emphasize that God is unique and we cannot apply our own standards onto God. He is truly glorious and it is right for Him to be honored above all else. This talks more about this:
I just disagree that God only cares about His glory. He also cares about His creation, and in special, humans, made upon His image. That's why Christ came, became man, and died on the cross for us. That is an expression of care. But in the end, that care mirrors His glory, and goodness. And his love, graciousness, and will to forgive.