Before attempting to "make" somebody a better person I would have to come to the rather self-important decision that I was qualified to pontificate on what would make them better. No thanks! I'm too vulnerable.
But, allowing for the moment that it was reasonable to make such a judgment, it still wouldn't work. It's hard enough to make changes in your own life, let alone in somebody else's. Look at the number of newlyweds who enter marriage hoping to straighten out their spouse's less attractive habits only to realise that it ain't gonna happen.
