Additionally, one of the more important criticisms that I actually shared with the OP is that it took me a few evenings to get up and running with Haskell around 2008-2009 on Mac OS X. However that problem has been just about completely solved by the Haskell platform (http://hackage.haskell.org/platform/) these days.
Also, recent activity in the Snap and Yesod web frameworks makes me more optimistic for Haskell adoption in industry, although it still has to clear a lot of adoption hurdles before it becomes more common.
My theory is that Haskell has a lot of usability problems. A programming language is a UI for programmers. Usability issues are always a sufficient explanation for market disappointments in any product or field.
Most notably, Haskell is rooted in a theoretical foundation that's essentially a major subfield of 20th-century mathematics, using concepts and notations which most programmers (a) do not understand, (b) do not want to understand, (c) do not need to understand, and (d) in many cases are not physically capable of understanding (eg, they have IQs < 140, or other sorts of subtle congenital damage to the math lobes).
As "LYAH" demonstrates, it's possible to teach programmers (or at least a certain subset thereof) to use Haskell without fully understanding it. But this approach has serious UI problems of its own. It's not very comfortable to use a platform whose semantics you don't understand. There's no comparable hidden complexity in Ruby, Python, Perl, JS, etc.
Laziness is also a significant UI problem, inasmuch as it becomes cognitively very difficult to understand and/or control the performance of your program. Typically in UI, when you find one UI disaster you find more - it shows that usability was not a principal goal of the project.
One of the difficulties in diagnosing usability problems of this type is that people rarely complain about them directly, because their complaint would typically be of the form "Haskell made me feel stupid." My guess is that for everyone who's succeeded in learning them a Haskell, there are four or five who tried it and came away feeling stupid. Not a very pleasant sensation.
I could not care less. The post is well-written, and makes a case. You can criticize his case, or even the facts he mentions or you could ignore them, but calling him a troll is totally unproductive (essentially it means: "his arguments are BS because he is a bad person, but I won't say what's specifically bad about them").
I also find that (to keep with Sturgeon's Law perhaps) 90% of uses of the accusation "troll" are misuses, mostly translating too "the guy makes arguments we don't like, and he won't go away".
Also, to everyone: he doesn't say that installing Haskell takes too days. He says it took 2 days to HIM --and AT THE TIME. Perhaps he wasn't using the all-too-might distribution you are using where it's one apt-get away...
Rather than downvote his posts or comments to oblivion, I recommend reading it all with a lot of skepticism.
For one example, he claims it takes two days to install the Haskell compiler. I can refute that from personal experience, or you could just consider that it's really implausible anyone would ever try out such a language. (And then visit their downloads page and see it's the same as Ruby or whatever: apt-get install or download an installer and run it: http://hackage.haskell.org/platform/ )
Edit: the post is from 2010. Present tense in the above is all wrong.