I wouldn't call it missed opportunity, they just decided they wanted to be the page you go to when you search on Google rather than the place you go to discuss and debate, and they succeed wildly at that. But yes, it's a shame that community wikis and information "compendium" type of threads had to be sacrificed. Sometimes I wonder if they wouldn't be better off creating a spin off site just for debates and open ended threads reusing the existing SO community, but then they'd argue there's reddit for that, even though reddit isn't quite the same.
How could StackOverflow work as effectively for such a broad set of topics with a small community?
I suppose I don't understand the point of the article as written.
Might want to change the "Expert-sexchange" (sic) typo :)
It's kind of an in-joke/meme for some people to write it like that.