We read in Hebrews 12:16 :
See to it that no one becomes like Esau, an immoral and godless person, who sold his birthright for a single meal.
Gen 25:29-34 tells us how Jacob "bought" the birthright due to Esau:
Once when Jacob was cooking some stew, Esau came in from the open country, famished. He said to Jacob, “Quick, let me have some of that red stew! I’m famished!” (That is why he was also called Edom. Jacob replied, “First sell me your birthright.” “Look, I am about to die,” Esau said. “What good is the birthright to me?” But Jacob said, “Swear to me first.” So he swore an oath to him, selling his birthright to Jacob. Then Jacob gave Esau some bread and some lentil stew. He ate and drank, and then got up and left. So Esau despised his birthright.
Gen 27 further gives a full account of how Isaac, old and weak in the eyes, was deceived by Jacob into believing that he was Esau.
As such, Genesis gives a picture of Esau as a simpleton who would sell his precious birthright for a cup of stew, but not as someone who was immoral and godless.
My question therefore is: Why does the author of Hebrews picture Esau as an immoral and godless person? Inputs from any denomination are welcome.