I don't think the denial relates to the guilt so much as it relates to the probability the person will be able to ditch this habit when they need to. Given that someone has an addiction problem, they're far more likely to overcome it if they acknowledge it is a problem. If they don't currently acknowledge, then things will probably get worse before they can get better. So perhaps OPs statement should be framed moreso as "realization is the first step to recovery", but I get where they are coming from.