Why Do Sentient Beings Not Attain Liberation?

Because the Manas-vijñāna constantly clings to the dharmas perceived by the seeing aspect of the Ālaya-vijñāna as "I" and "mine," it becomes bound by dharmas and thus is not liberated. Whatever dharmas the Ālaya-vijñāna perceives, it manifests them like a mirror. When the dharmas thus manifested are apprehended by the Manas-vijñāna, it considers all these dharmas to be "I" and "mine," thereby giving rise to craving and attachment. If the Manas-vijñāna clearly recognizes that these dharmas are unmistakably those of the Ālaya-vijñāna and not its own, it eradicates ignorance, eliminates the view of a self (ātma-dṛṣṭi) and the view of dharmas as possessing inherent self (dharma-ātma-dṛṣṭi), attains right view, ceases to grasp these dharmas as "I" and "mine," and is thereby liberated from all dharmas, attaining Buddhahood.