Why did Ibn al-Qayyim cite weak hadiths in his book "Al-Dāʾ wa al-Dawāʾ" (The Disease and the Cure)?

Ibn Al-Qayyim's book "Al-Da' wa al-Dawa'" (The Disease and the Cure) discusses forbidden desires, their causes and remedies, and sins, their effects and punishments, along with a discussion on good and bad endings. He clarifies that the origin of the disease is sins and disobedience, and its cure lies in realizing monotheism (Tawhid) and sincere love for Allah, coupled with hope for His forgiveness. The author included weak hadiths in the chapter on encouragement and deterrence, which is permissible under certain conditions. To avoid weak hadiths, it is recommended to acquire the edition published by the Islamic Fiqh Academy.