I understand the frustration. I am sure he is not the only one. I would suspect that we do not mind who wins from what country. Why should we? But, these things usually decided way ahead of time (we don't just make these the day before) when parties meet together.
Alot of things come into play, sponsor rules, country/state/county rules. Fulfillment feasibility (IE say if you won a big block of cheese, shipping it to outside the country its in would be impossible due to import laws) among other things; like some companies do not allow their products to enter specific country's for various reasons...
One, non-wgt related example comes to mind is when I was looking for battery charger, the better kind could only be bought in Europe because in the USA, that company's got challenged for patent infringement, so court issued a stop order. Which mean, that company legally cannot sell or do anything with that product in country.
I realize the above mentioned example is niche and likely not what's happening here, but it does go to illustrate that the kind of issues that may prevent certain countries from being eligible, is beyond anything one can consider.
For right or wrong, that's what it is
-wgticon