It's probably for simplicity's sake. It's easier to spread the policy over the entirety of the PAL regions than limit it to just Germany. That said, German censorship laws really need to ease the **** up.
Wow, that's a ridiculous time. The watershed time here in the UK is 9pm, so they should have at least picked around there, makes more sense than 11. If you work a normal 9-5 job, 11pm is a bad time to turn on your console. Or they could I dunno, have better age restrictions/parental controls.
Talk about segregating their market. This will likely reduce sales in Europe, no one wants restrictions on their gaming, especially 18+ people. Also, why till 3 am? how many kids are waking up at that time looking to play violent games?
