It's not the legal status (fraud is already illegal), it's proving that it is indeed a scam rather than some dumb shit they actually believed, as well as knowing that it's more likely to trigger a persecution complex and doubling down than improve the lives of the victims (because if it's a plot to harm their religion, they don't have to feel like idiots for giving the scammer money).

It's a different story if the religious scammer openly admits that it was always a scam and just doesn't care what anyone thought of it. Easier to prove and the victims are already angry and feeling like idiots for falling for it.