Why do Muslims kiss the Black Stone if they do not worship it?

Can we blame someone for kissing the envelope that contains a message from his father, for instance?! All rituals of Hajj are meant to establish the remembrance of Allah and to indicate obedience and submission to the Lord of the worlds. They are not meant to worship stones, places, or people. Meanwhile, Islam calls for worshipping one God, the Lord of the heavens and the earth and what is between them and the Creator and Sovereign of everything.

{I turn my face towards the One Who originated the heavens and earth, inclining to true faith, and I am not one of those who associate partners with Allah.} [302] Surat al-An‘ām: 79.