What about the existential dread route (sorry!). "If I don't quit this, then I'll never do X.. and my life amounts to nothing". It might be blocking a lot of life goals that will never come to be.
Isn't this one of those things that usually ends up having the opposite effect it's supposed to have? As in, people who scold themselves about their specific addiction are likely to include the self scolding as one of the rituals related to the addiction. The feeling bad part / existential dread can be as much a part of the addiction itself as the feeling good / placated part.
