So it did not matter what level of life or intellectual capacity they had, they were still not able to read it because they were not obedient to God, therefore they could not have the understanding needed.
They listen to the society, to the influence of the experts in their society. They listen to others, but they would not listen to God and read His Word.
The root of sin is failing to prioritize God above everything else. Therefore, He is not honored and praised as He deserves. The people are not necessarily foolish in the sense that they lack intelligence, but in their rejection of God's sovereignty over their lives, they knew God, not in a faithful and submissive way, but simply as His existence and attributes can clearly be seen in creation.
