indeed, mind our own business! but if they ask for help, why not assist them. we are just humans who always mistakes in our lives. and we have our lifetime to correct whatever we feel is wrong with our life.
but do remember, don't shove to others about your piece of advice. let them voluntarily ask help. because if you will force them to, the more they will avoid your presence.
When it comes to issues with addictions, it better for the individual involved to seek for help and doing that will show that he is already made up his mind to break out of that addictions, and for that it may be most appropriate to avoid interfering with the ways the tend to handles their gambling investment and wether or not they want to stop gambling.
And just as you have said, if you force them to seek for help, they may start avoiding you and by so doing it may lead them into more problems in the future, so it's better for you to always mind your business and not interfere in they business unles they ask for help from you at some point in time.