People who are stubborn about taking the right precautionary measures wont mind investing with everything they've got. My conclusion on them is that they are high-risk takers. Taking risks without thinking properly. The best way for them to learn and change is if the risk costs them a lot of money. It will force them to learn from the mistake. It is not everyone who listens to advice and puts it into action immediately. The stubborn, ignorant ones will listen to the advice, then do what they intend to do, irrespective of the consequences.
Exactly, until they learn the hard way, they won't heed advice given to them and then, they will be the one to advice themselves actually. One can only help by giving them advice but the choice is theirs to either protect themselves from harm or do what their minds say and face the consequences later on because they can't be forced once they make up their minds. So allowing them to have a taste of their wrong decision is just the best thing to do.
They actually have their own choice if they follow or not, but if they try those risky thing just like common action done by lots of newbies.
For sure later on they realize that they made a bad decision and feel bad on the mistakes they have done.
That's why experience is best teacher right? If those people eager to bounce back, maybe they might learn from those bad faith they experience. Then try to do more better judgement on their next investment attempt, since for sure they don't want to lose and commit same errors again.