There is a lot more to this story that a bunch of wingy people who were dupped by a promise. The promise was happiness and the end result in Guyana was underground isolation chambers for people who wanted to run away, the money threats & taken, the beatings, hoping for death, assassination security parameters.
What drove Jim Jones out of San Fransisco (he was on city council: real estate, housing) was a couple of reporters.
The Jonestown wiki article is huge. One of the references there is:
CNN November 19, 1998
Jonestown massacre memories linger amid rumors of CIA link