I've learned the hard way that people never change unless they want to. You can't ask comeone to change, you can't force someone to change, it'll probably only have the adverse effect if you try.

People who have a destructive behavior will probably only wake up and smell the coffee once they lost everything and hit rock bottom due to that said behavior. But as long as people around them allow, put up with or endorse that behavior, then they'll never change, because the human mind has a "why change a winning formula" policy.