Why does God need us to love him?

Is it for his own sake and personal pleasure?

No, it’s not, because our own state of mind can’t change anything in God’s State of glory. Although He loves us, God doesn’t need our approval, amazement or even love.
As I said in other chapters previously, God is instructing us / advising us / wishing for us to love him above everything and everyone else, because only in loving him to that degree that we can dwell in him, spiritually speaking.
God is not only a conscious being but He is also a loving person.
If we loved God and allowed him to transform us into loving beings like him, then our dwelling will be in him and him in us. We could become at One with him. But we wouldn’t be able to live in him if we were not willing to be transformed.

1 John 4:16 ESV “So we have come to know and to believe the love that God has for us. God is love, and whoever abides in love abides in God, and God abides in him.”