Number of cores on a system has nothing to do with it. If you sat down and wrote a few thousand lines of code in both of these languages, the natural architecture presents itself the same way. Erlang has "nothing to do with" actors either. But this language is de facto the standard way to refer to this kind of message-centric architecture. The largest influencers of the actor model are simula and smalltalk. Denying the relationship is beyond absurdity.