The 'addict' blames the addiction for his problems instead of himself. It's not his fault - it's the fault of the addiction, and hence he is not responsible.
In fact, every time the addict indulges their addiction, they make a choice to do so, and they are responsible for their choices. The addict wants to indulge his desire without taking responsibility for it.
Not only does the addict avoid having to take responsibility, but they get to claim victim status - by being victims of addiction.
See