steal code from non-opensource projects, ignore licenses and do other shit like that
That's a lot of incorrect assumptions there.
They didn't steal any code. They didn't ignore licenses either. In fact, the only reason they had a judgment ruled against them is because they were taking monetary donations. Which was interpreted as "profiting".
They reverse engineered a process without stealing anything. They didn't even circumvent DRM, which is actually protected by law on the grounds of creating personal backups and data/software preservation.
You're either very ignorant on the subject or you just ate up Nintendo's BS.
Actually yes. The people that run afoul of the GDPR are the people who run the instance servers. The code writers are not the ones legally responsible.