The participants seem surprisingly ignorant of the state of the art in concurrent programming. Message passing architectures are old hat, and have been shown to be scalable; a lot of work is going into transactionactional memory and other non-blocking strategies, and so on, but I don't hear these being mentioned even in passing.

The Eiffel SCOOP mechanism was proposed over a decade ago, making the idea generations old in the software world, yet a functioning product still hasn't shipped. Why is that?

I'm not convinced that SCOOP can work. The problem I see with it is that it allows for arbitrary sharing of state among concurrently executing objects. If it can be made to work then the compiler will probably have to make such conservative decisions wrto synchronization that performance will be a tiny fraction of the theoretical optimum.

Its one of those ideas that have a seductive elegance at first glance but ultimately turns into a dead end.