If all those people can be informed about bitcoin, how to earn money in bitcoin? I think they would have invested in Bitcoin and they could have made money from it.
it's not easy as you imagine, because they should learn from the beginning to know how to invest and make money with Bitcoin. They are already in gambling and sometimes make some profit from that, so that situation is hard also to leave the routine immediately or change the activity to be a trader. if I were you and have the chance to talk with them, maybe I can do it step by step to tell what they should to do to leave, don't force it, let it run as it is.