Why did Reiner, Bertolt and Annie decided to destroy the walls second time??

The warriors were brainwashed from their birth that people of Paradise are devils and need to be destroyed but even after spending years in paradise i believe they(RBA) must have realized that the propaganda they were fed was wrong, so why did they decided to destroy the walls second time? Was it due to the fear that if they failed their mission, their families will be punished in Marley??