The problem with what he said is that he seems to be dismissing "hybrid" languages like Scala as equally overrated or worse than pure functional languages like Haskell

His point is that concurrency is something you still have to consider carefully and design in from the ground up and that no language is a silver bullet for this essentially hard problem. I think he's also probably right to worry that people will think that because they're using Scala and actors, for example, that they have automatically created a correct, performant concurrent application.

That doesn't mean though that languages like Scala don't give you better tools to deal with these issues than Java.