Total Truth from untruth :)
I agree with you 100% I think doomsday cults take advantage of the natural fear we humans have of what tomorrow will bring. It seems to me that we humans naturally have the tendency to believe that "things were better in the past" and thus we assume things (in general) just perpetually continue to "get worst".
Cult preachers usually tap into this fear by preaching their doomsday message. "The world is ending any day now, we know the secret to survive". That's why some of the biggest growth JWs have experienced happened in the years prior to 1925 and 1975, years JWs expected the end to come. Thing with JWs is that once you are in, it's hard to get out.