It has less to do with narrow minded thinking and/or shipping costs and more about international law. Even in the US, there are all sorts of rules about running contests. Most states have the same basic rules, so most national contests are valid. Rhode Island is unique because the state law actually requires the company to file a legal statement before it can run a contest in that state. That is why you see some contests say RI isn't valid - simply because the company didn't want to file the contest with the state.
Contest law varies even more between different countries. If you were to open up a contest to people all over the world, you would have to research the law in every single country on earth, to avoid getting yourself in legal trouble. For a typical promotional contest, this is just too much work. The legal fees for the required research would be much more than the payoff of the promotion. Additionally, there are some problematic legal questions inherent in any international contest. For example, if something were to go wrong, -- say, the prize was lost in shipping -- what court would the contest winner go to? It would be a very tough legal question just figuring out who had jurisdiction.
What it comes down to is that it's just too much work for a company to find out how to cover themselves, legally, in multiple countries and in all states. After all, the typical rules and regulations of a contest running only in the United States take up 20 or so paragraphs. Just think how small a company like Storm would have to make the print to cover itself internationally!
