I am sure many of us can't be bothered if a gamblers lose everything and drop dead penniless. I am no different.
But it is seldom that cut and dry. Inevitably the family, the relatives and then society has to carry the burden. Taxpayers will have to foot the bill. Abuse of spouses and children are the usual consequence. We must be kidding ourselves if we think there is little or no impact. This is the reason why casinos and gambling are heavily controlled by every country.
We control drugs, guns, porn etc for similar reasons. Again I can't be bothered if these people overdose or shoot themselves. But they have the habit of harming others who are innocent to pay for their drugs, to show their manhood.
Notice governments do not regulate ice creams. Ever wonder why not but for some crazy they control guns, drugs and gambling? Notice that they are pretty universal across the world. Well the whole world cannot be wrong.