Well we can look at it this way, how about those countries that consider gambling as illegal?
And we have seen that their reputation as well are not affected, so I think it will have the same outlook as those countries that legalized it. And if I'm not mistaken, there are 1st world countries that already legalized it and so far we haven't seen any effect on them in the world economics.
Could be that this countries have matured already so it's ok with them to legalized it winning any dire consequences.