Why is this condemnation expressed as being general, while their co-religionists do not condemn them?

Imām Ibn al-Jawzī (d. 597/1201) summarized the scholars' opinions in his book "Zād al-Masīr" as follows:

1. They will curse him in the Hereafter. Allah Almighty says: "Then on the Day of Resurrection you will deny each other and curse each other." [Al-Ankabut: 25]. And He says, "Whenever a nation enters [Hell], it curses its sister nation." [Al-A'raf: 38].
2. The word 'people' here refers to the believers. [Ibn Masʿūd, Qatādah, Muqātil]. According to this view, the phrase would be an example of something general that is intended to mean something specific.
3. The curse from the majority can be referred to as the curse of all people, by giving precedence to the judgment of the majority over the minority.