...when Rebekah had conceived children by one man, our forefather Isaac, though they were not yet born and had done nothing either good or bad—in order that God's purpose of election might continue, not because of works but because of him who calls...
Romans 9:10-11
God didn't choose Jacob because he was a great man. God chooses whom He will for His own reasons. Esau wasn't hated because of anything he did, but because of who he was and wasn't.
Who is Esau to object to Isaac's calling? The nations to object to Israel's calling? Who is the pot to question the potter or the vine to question the gardener? God's choices aren't arbitrary, but they might appear so. He doesn't ask our opinion or owe us explanation.