> That's the same situation languages like Factor and even Haskell saw seven years ago. The former is more or less dead and and the latter still never "broke out".

Kind of a nitpick, but "breaking out" was never a goal of the forces behind Haskell, and in fact contrary to their stated desires. Much of Haskell's value was always (and continues to be) its variety of tools for expressing the semantics of the problem the code tries to solve — features which we now see spreading rapidly among mainstream languages. The rest of its value (and its primary purpose) was as a research tool for developing such features. There's still a lot of work to be done in exploring that frontier.