Varahi Tantra says that in the age of Kali yuga, most stotras are cursed by Parashurama and hence are ineffective. While listing the ones which are free from this curse and hence suitable during Kali Yuga, it is said, "Gita of the Bhishma Parva, Vishnu Sahasranama of Mahabharata and Chandika Saptashati' (Devi Mahatmyam) are free from all Doshas and grant fruits immediately in Kali Yuga."
Why did Parshurama curse the strotas? Why did he didn't curse others? Should we still practice the cursed strotas and what are the harms otherwise? What happens if we follow them anyways?