Why Did People Remain the Silent Majority during the 1979 Revolution in Iran?

A question comes to mind that why did people remain the silent majority? Those individuals did not see what the mullahs did to Iranians during the 1979 Revolution in Iran. Hussein Dehbashi interviewed Mullah Hadi Ghaffari, who said he travelled to Palestine and met Yaser Arafat to get guns and bullets to Iran illegally. Also, Hadi Ghaffari disclosed that he went to Libya and met Gaddafi, who gave him firearms and ammunition to be brought to Iran illegally. 

Mullah Ghaffari did not confess how the weapons used by the revolutionary people to kill their friends and blamed it on the security forces and attacking people randomly. 

Therefore, Iranians feared death and wanted to be safe and remained silent to avoid death.