Because the lock-free Erlang meme doesn't die:

  1. Erlang has locks and semaphores [1], receive is a lock, actors are semaphore. Erlang chose a 1 semaphore/ 1 lock per process model
  2. Erlang scales better not because of being lock-free (see above), but because it easily uses async compared to other languages
  3. Async prevents deadlocks not Erlang being lock-free (see above)

Some 4year old reading http://james-iry.blogspot.de/2009/04/erlang-style-actors-are...

[1] http://en.wikipedia.org/wiki/Semaphore_(programming)