This may miss your point, but I would easily argue that Scala is a "web language," just as Java is and was before it. Scala's focus on concurrency helps drive this point, as it's not response time so much as throughout given IO constraints that make a good environment for web applications.
Yeah, I don't really think people would argue scala doesn't make sense for web dev. I think the main is that webdev can generally tolerate GC and it's not worth giving it up.
