Reality Rosa: RPG alt-history

My inevitable critical take is that this is Great (wo)Man Theory, which is inherently divorced from reality. The KPD didn't take a huge turn for the worse after Rosa was killed, they reoriented around the valid understanding that social democrats were as dangerous to them as liberals, monarchists, and fascists. A KPD that realized this less completely would've been crushed earlier and antifascist partisans would've been weaker. Repredicting history is inherently speculative, but the more likely immediate result would have been more strength for the Nazis, not world revolution, though it's also reasonably likely to mean very little because the material conditions would've been the same and the KPD was robust.

An alternate history where Germany is the source of European proletarian revolution should depend more on a change to material conditions and mass psychology. Imagine what it might take to make Germany immune to antisemitism or racism more generally (it's still far from immune to either). Or imagine what could tip the scales against fascist vigilante violence and takeovers, like a stronger communal economic base to falk back on.