Forget about the Manson Crime Family when it comes to cults, because at the end of the day, the Manson Family was a family of criminals but Jonestown was a cult that ended horribly with several hundred people, if not more, murdered by their leader, a paranoid dictator/terrorist, Jim Jones. This was a real cult, a group of Americans lost inside the United States, the country of their birth, looking for a new concept that would make their lives worth living.
With regard to the paranoid evil aspects of Jim Jones, someone strong enough mentally and physically could have taken on Reverend Jones and said "enough is enough," for lack of a better phrase. "What you are doing is wrong and we should not be a concentration camp in Guyana, but instead a socialist communitarian community of people living and working together to make a good life for ourselves and our families. Jonestown could probably still be in business today and thriving because, with another philosophy, it would have had the structure needed to be successful.
The People's Temple and Jonestown had the vision and the people to be successful, but they lacked the necessary leadership to succeed as a community of people who would care for each other, where no one would go hungry and live in poverty or be a prisoner of addiction, and who would have the basic health care needed to be successful. They would have been able to produce what they needed to live well in Guyana.