This discussion is not about gambling, it is about investing, but I will use gamblers to make an example.
Using gamblers as an example who start out with just the intention to have fun maybe and then along the line turn into addicted gamblers that gambling begin to affect other areas of their life like their wellbeing like they stop spending on some important things just so they can make money available for gambling. Now talking about investing, I think it is possible to become addicted to investing so much that it begins to affect your wellbeing, like the person stops spending on other important things like good food, good clothes etc. just so they can have more money to invest? Do you consider that kind of addiction dangerous and not good?
While it may be easier to think that having an addiction towards something that is positive or productive is better than having one's self addicted to detrimental or bad things, we cannot rule out the fact that anything that is too much is never good for anyone. Regardless of how much of a great thing a productive addiction provides, if it hinders a person from living a well-balanced and fulfilling life, it will never be a good thing. Thus, we can say that the kind of addiction you are talking about along with all the other addictions out there are dangerous and not good for anyone.