Game console manufacturers are trying to screw you. And if they're not, the people who make the games are. And if they're not, the people who control the licenses for the games the developers make are trying to screw someone else, so they sell the rights to the same property to three companies in three regions, and the developer has to pay three times to release the same game in three places, so the console manufacturer makes it possible to lock out games from one region when played on console from another region.
Translation: Sometimes you have to get tricky if you want to play games from JP/US/EU on your console, from EU/JP/US.
- Nintendo 64