While the actions of Rebekah and Jacob are rightfully frowned upon, the inappropriate actions of Isaac seem to be overlooked.
Isaac must have been aware of the Lord’s prophecy given to Rebekah (“the elder shall serve the younger.”).
He also knew that Esau had despised the birthright and sold it to Jacob.
Furthermore he was unhappy about Esau’s marriages to Hittite women.
Yet he persists in trying to give Esau the blessing – because he was his favourite son