People who have gone through bad even traumatic experiences of one form or another can be in a vulnerable state and in that state embrace a belief system that will alleviate that stress that they are going through with a hope that they can cling on to and give them hope.
It is not a phenomenon that is restricted to JW`s. only.Many groups religious and otherwise offer such hope.
The Bible says that "hope is the assured expectation of things hoped for "
however false hope is a prescription for disaster emotionally ,physically ,and mentally.