Even when pushed into a dead end, the Primordial Heavenly Venerable had not the slightest intention of compromising.
He left no way out for Jiang Lu, nor for himself.
He laid all his cards on the table and straightforwardly expressed that even if Jiang Lu stopped suppressing him for the sake of the Queen Mother of the West, he would not change his mind.
His goal had always been to Unlock the Forbidden God Land.
In other words, he was negotiating with Jiang Lu.
Either eradicate the possibility of him Unlocking, but at the cost that the Queen Mother of the West would never be resurrected, or grant him freedom and time to research the resurrection of the Queen Mother of the West, but at the same time he would continue his attempts to Unlock. Then, all of Jiang Lu's previous efforts, including the sacrifices of the Queen Mother of the West, would be in vain.
To concede once would mean losing ground and setting a precedent, followed by a relentless cycle of repetition.