Here is a central idea of Judaism. The idea of Kedusha pulled them both to Canaan. Major decisions in one life are sudden and intuitive. Secondary decisions are based on careful calculation. Avaraham and Terach made a major intuitive decision.
People respond to a stimulus.
The Dor Hamabul responded to the challenge of beauty. Their philosophy was that one must succumb to the power of beauty and give in to the aesthetic challenge. They responded to the fair women who were the symbol of beauty. Modern man is still captive to the aesthetic experience, the exploitation of enjoyment in life, making use of all that is available. The serpent in the garden of Eden was the first one to describe this aesthetic pull when describing the Eitz Hadaas as Nechmad L'aynayim.