عَلَيْكَ comes into focus when someone receives guidance but knowingly persists in conduct opposed to it. The Qur’an is not only to be read; its teachings are also meant to guide conduct.
Example: Two people read the same instruction about others’ rights. One corrects a past injustice, while the other continues to withhold people’s rights knowingly. Reading the same verse does not make their behaviour equivalent.
The warning also encourages reform: when a fault becomes clear, a person should repent, fulfil the neglected right, and bring future conduct into line with guidance.