The joke is that they embrace the behaviour they otherwise look down upon when they play the game. Nothing to do with games causing people to become violent.
It suggests that Europeans embrace the behaviour when they play the game. The people who purport that extreme behaviours in media (games, TV, movies, books) translate into real life behaviour are making a false equivocation that such behaviour will carry over into reality, which has been shown to be false.
Look, I am not arguing with you that video games do not cause people to behave poorly in real life. But I will push back on the idea that that is what the meme is suggesting. It only suggests they embrace it when they play the game for the first time, nothing more. We shouldn't extrapolate further meaning beyond that from a silly joke.
You could argue it's the opposite -- video games provide a healthy outlet for aggression. When I'm angry at the state of the world I'll go shoot space rhinos and space bugs and hivemind robots. I'll roleplay a feel good setting where I'm the indisputable good guy with all the power to kill the indisputable bad guy.
And sometimes I just want to see shit blow up and break