Gambling can destroy lives, but many people do (sorry to use the phrase) gamble responsibly. Much like alcohol can destroy lives, but many of us can enjoy a drink without it being a problem. I don't think the same is true of tobacco - that's always bad.
The grubby quick loan companies are far worse, and those I do have a problem with. I don't really have a problem with the gambling companies, but I imagine it would be better for our society if their adverts were restricted more.