I don't think gambling should be called a addiction it's not something bad or horrible as it's always is portrayed. Not all our alike, not even our fingers are the same size, each one finds a different passion which keeps him sane so I would call it a passion, i believe each person is sane enough to decide for himself, and so I feel each one can make his own choice without being subject to humiliation.
It's call adiction when someone can't stop gambling and its bad or horrible when that someone lose control and ruin his/her life because of it.