To paraphrase departed Dan Sydlik: Why do you think God gave you a brain, and hands, and strength?
There are some things you are meant to do for yourself! Funny, you didn't wait for the Holy Spirit to make you *start* smoking, so why should it help you stop? Your decision, your strength, your action. Same with the cases of illness such as the one you mentioned; people make decisions (even unwise ones), it's their right and prerogative; why would anyone expect the Holy Spirit to get involved? It's sad and terrible when people lose to seemingly random ailments or tragedies befall them that are not of their own making (tsunami's, dementia, etc.) but again, what has that to do with Holy Spirit? Holy Spirit didn't cause them so why should Holy Spirit be expected to fix things up?
Look for sources, not scapegoats. Take responsibility for your own decisions. When the reason for tragedy (or anything else for that matter) isn't clear or isn't able to be tested satisfactorily, don't blame what you perceive on "Holy Spirit" as if it had shortcomings, rather, take it upon yourself to learn more than what you know now and give understanding a lot more time. Grieve if you need to, but don't join any lynching parties, you may find out later that it was you who was in the wrong.
AnneB