The real point is that Haskell is quite good in many areas and is excellent in parallelism and concurrency. While other languages are excellent in concurrency and not so good in other areas.
Those many languages are the answer for the sole field of concurrency and Haskell is the answer when you combine many fields, one of which could happen to be concurrency.
Sure Haskell is good for more than just concurrent programming, but the article was leaning on concurrency and parallelism in its comparison with Node.js
And I should also point out that said "blub" languages can also implement those features which they lack that Haskell includes by design. Some have better features than Haskell, IMO (ie: Qi/Shen sequent types and the ability to turn the type system off when you don't need it).
Again, Haskell is a good language. I just don't see it as a "cure." There are many other options.
How can the "blub" languages implement Haskell's type-classes as libraries? Or generalized type inference? What about Haskell's higher-kinded polymorphism? And pattern matching?
Lisp can do some of these, but it is not exactly a "blub" language. Is there a nice comparison of Qi and Haskell? Once you implement such a large, non-trivial system (such as an advanced type system), I really doubt using Lisp macros rather than implementing a compiler is easier. Macros that do such non-trivial things also do not compose well, so I doubt Lisp is beneficial for this purpose.
No one has characterized the right task scheduling outcome.
What tool will give us the the best task scheduling outcome, with appropriate effort?
Node schedules each task to run until it is done or you tell it to do something else. This seems simple and honest. The impact of excessive CPU load is obvious.
Other tools offer automatic task preemption and time slicing between tasks. Once CPU load gets high the impact is much less obvious.
If I read the article correctly it's simply a matter of concurrency and parallelism that's important.
There are a host of languages that do that quite well and Haskell just happens to be one of them.