This is all set up so they can rake over the richer countries without entirely locking themselves out of the less wealthy countries.
In a world with region locking: "Let's charge $50 in Burgerland and Poutineville, because they'll pay it. But we also want to make some money off their neighbors to the south, who won't pay $50. (Maybe they can't, maybe it's the burned DVDs for sale on the street for $2.) But now we have to stop the people we want $50 from, from importing the $10 copies. Region locking!"
In a world without region locking: "Let's charge $50 in Burgerland and Poutineville, because they'll pay it in order to have the content right now. We'll wait until the popularity goes down so that it's worth no more than $10 anywhere, and only then will we send it to places they'll only pay $10." By that time, those $2 burned DVD vendors have saturated the market so it's not even worth $10 there any longer.
However, it seems to me there is a form of "region locking" that follows the same general divisions. It's called a "language". Don't ship discs with all languages, just the one relevant to the buyer. Monolingual Americans are not going to watch Game of Thrones in Spanish just to get it cheaper.