Yes there are happy endings. I know a couple who have a great relationship but he was in recovery going to meetings etc and they've been together through it all.
My thoughts.. If he/she grew up in a healthy environment, then I think they probably have a better model then say someone who grew up with alcoholic parents and then became an alcoholic.
Or if the alcoholic wasn't abusive or completely destructive to the family then there is maybe less resentment built up.
But yeah, sometimes I wish there were more 'good' stories.