@Edent Open Source already has a diversity problem. Requiring real names will effectively prohibit lots of disadvantaged groups from contributing – the kind of people who are already facing harassment. With real names this harassment will escalate into calls to one’s employer, threats of physical violence and maybe not only threats.
At the same time, it won’t really prevent any abuse as you explain. I mean, a state-level actor can even coerce a real open source contributor into cooperating. With the scene being so international, they usually won’t have trouble finding one that’s within their reach.