Well, what is addiction in games?
The way I look at this, people go to games to escape. Now, there are other reasons. Gambling addictions are usually fed by debt.
The games themselves don't deliberately cater to escapism though (well actually, there are some that borderline it). They weren't written for escapism.
Gambling games are, I believe, entirely different though. Maybe I'm too pessimistic, but I tend to think they are written primarily for people with addictions.
For some kind of comparison, an example of a gambling game that I would be fine to make would be, say, poker. There is clear value in the game itself, although money is key to the gameplay.