I would suspect that it's because a ruby ARC would require thinking more about references (the strong/weak paradigm would, I think, need to come into play) whic

I would suspect that it's because a ruby ARC would require thinking more about references (the strong/weak paradigm would, I think, need to come into play) which isn't really a concept in Ruby. I think it would be difficult to ensure code written without arc would still run properly. But I agree with you. I much prefer ARC over any GC I've come into contact with.