> You can accept the points I made or discuss them, but this is just moving the goalposts AGAIN.

I am really not. My claim is a general one about Scala's kitchen-sink design philosophy, and why it's inappropriate for an "big engineering" language, as opposed to fast development languages like Ruby or Perl, yet it is you who insist on focusing on detail, which is part of the problem. So I responded to the detail.

> Why should that happen?

Sorry, I made a mistake there. The compilation will break when you try to pass the object to a method that accepts that structural type.

> It's pretty damning to see that in the few months in which macros existed, more useful functionality was written than for Java annotation processing ever.

You are most certainly wrong here, though I can't prove it. You're forgetting that 99.9% of Java code is not open-source. In the organizations where I previously worked we used annotation processing where needed.

> Again, just because you don't see the benefit or the reasoning behind it, doesn't mean that the brightest minds in our profession are all wrong.

Those brightest minds are usually the brightest minds in PL research. I don't think it's a coincidence that most of the languages designed by them, while brilliant in some respects, are not widely adopted in the industry. You can only attribute some of that to marketing. I also do not think it's a coincidence that all languages developed at Google, a company that knows a thing or two about large scale development, follow the Java philosophy.

I am not a PL researcher and not particularly interested in PL research aside from learning a thing or two about the potential of programming languages, but I am very much interested in moving the software development industry forward. Some of the things PL researchers focus on I find to be genuine problems with software development – like taming concurrency, which Haskell does a good job at though perhaps at an unacceptable cost to the industry, and Clojure and Erlang do an excellent job with despite their lack of PL researchers – while other areas, like developer productivity, I find to be the wrong problems to focus on.

Let me explain the last point because I think it's important. We have some good languages (Ruby, Python) that are excellent for productivity, and are extensively used in some domains. Where those languages fail - concurrency, large-scale engineering - productivity is less of an issue.

But then I found Clojure (and, mind you, I personally prefer static typing and think it's generally better for engineering, though I recognize this is just a means to an end), and saw a language that is probably as "productive" as Ruby, yet actually tackles the big issues (like making sure some careless team member does not introduce a very hard to find race condition).

I think Scala takes powerful though complex features and channels them – unlike, say, Haskell – into all the wrong places (productivity), and at the same time makes it impossible for a mere mortal to understand how a basic collection is written. You can argue details all you want with me, and say that you could do this and could do that, but a language that makes collections the domain of experts without at least fixing the real hard issues, is just plain misguided.