I don't like a nation of sport gamblers as they would be in default debt really soon because no one would really work,all of them would have their mind in their betting.
A nation of sport gamblers will have the problem of having citizen who are mostly Irresponsible. The gambling will not affect everyone making everyone irresponsible, but it will surely have the number of irresponsible people more than the responsible. The irresponsibility is people who gamble without control, and those that will do anything just to keep getting money to gamble including involving in crime.
For a country like us, since when I have the ability to understand what gambling is, I saw a lot of problems as well. Crimes for one, and then parents becoming irresponsible like would just go and play all day without taking care of their kids. However, this is just prominent in provinces here because of the proliferation of illegal betting, underground cockfighting and others and it is being control by a group of powerful men and that they have corrupted and bribe the police and even government officials. On the other hand on the city, we have big casinos and you can see the same pattern though. Because when I go, I see a lot of gamblers who really trying their luck, just average joe who want to make it big by winning. We have a term here, "one day millionaire", and that's what their goals is. So I guess I have witnessed what a nation of not just sports gamblers, but gambling in general looks like.