I suspect the reason why this is being upvoted and what it actually says have nothing to do with each other. This is a bit of an academic debate about very precise details of exception handling, not some sort of takedown of the Haskell hype.
"Like most of Harper's articles about Haskell, this is both mostly true and an elaborately constructed troll where it's impossible to tell whether he's getting some lulz or merely piqued that nobody uses ML."
Bob Harper is a pillar of PL research, I think the credentials of his detractor deserve just a tiny bit more scrutiny. It's one thing to refute his assertions, and it's something else entirely to dismiss them as "troll" or "butthurt".
It looks like that comment is from the author of a few popular-press PLs books (most recently Real World Haskell), so probably knowledgeable, though not Harper-level accomplished.
It looks like most of the folks in the Haskell reddit community are taking it with good humor; I read that comment as a wry tweaking rather than as outright dismissal. Language nerds at play, fun to watch.
In the event that you really are interested in the topic at hand, you probably ought to read the followups on http://www.reddit.com/r/haskell/comments/y74vn/robert_harper... .