>>724782536
Because those who usually fall to Chaos in universe do not have the meta knowledge of the setting we do. They just see, "hey my life under the Emperor sucks, these other guys are saying my life would be better under other gods." while the Imperium hides it so much that the vast majority of people do not understand why Chaos is bad. We on the outside know full well the lore and the damnnation that awaits > 99% of chaos followers who don't end up daemon princes.