I am in Germany now. Can you tell me why this is not the case in mainland Europe? Is it much better in Europe to do side-project in lieu of the fear of getting sued?

I don't have any experience in this. I simply hear less fear about getting sued when you're in the right (I don't know how it is with side projects, I was more reacting to the issue of getting sued when you're right). I think the legal costs of defending yourself aren't so extreme in Europe. Also, I think there's less suing culture in Europe than in the US. All those stories of people suing the microwave manufacturer for failing to warn about drying cats in it or cafés not writing "Warning! Hot!" on the cup etc. In such cases people can get extreme amounts of money in the US that is less usual in here I think.

I am America. I am questioning why it is required to hire a lawyer for my example above

Depends on what you mean by "required". Is it required by law? No, probably not. If you actually want to win your case, however, you're going to need a lot of knowledge about the laws in question as well as court and legal proceedings to stand a chance, or your opposition's lawyers are likely to win the case on some sort of technicality because you didn't provide some document at the appropriate time or something like that.