And most people I talk to who do not believe the lie that "people are inherently good" usually have not taken it to its true conclusion that there are evil people out there plotting evil and destroying people's lives. (including the lives of their own children)

It's not a true conclusion because there is another option, that there are people out there capable of evil and good, and not necessarily purely evil. Their conclusion could very well be that there aren't purely evil people like there aren't purely good people, but degrees.