I would like to introduce you to a Steam Group: for UNCUT!

Dead Island is so bad that I'd ban it from my country too.

I don't know if you are trolling or really don't understand the issue?

quick explanation:
the law is about protecting children from witnessing graphic violence.
most countries have some kind of organization that rates video-games. (ESRB in the US)
In Germany when a game gets rated [Adults Only 18+] the retail store selling the game has to check the buyers ID for age verification.
Many Stores like the Steam-Store don't stock 18+ games, because they don't want the hassle to verify the buyers age. So, Game-Company's produce cut-versions of their games that get a [16+] rating.

Its absolutely in Valves hands to implement a age verification system.

Trust me, it has nothing to do with our government. German adults are allowed to buy and import indexed or uncut-games from abroad, but er have to make sure then, that no minor will get access to this game.

As a matter of fact, Valve is violating German law since they are selling 18+ rated games without any kind of age verification (which is mandatory in Germany).