I'm siding with spolsky here. The ultimate goal you have in mind is defining. Since building a community is hard and is the hurdle that kills most attempts, people will often see it as the goal. In many cases, it might be the goal.
Take Wikipedia as an example. Community is necessary but it is not the goal. The goal is encyclopaedia making. Most online communities do not produce a wikipedia.
What this adds up to, in theory, is sacrificing some community building ability (more sites will dies from under participation)for more Q&A ability. While more of the remaining will produce a good archive of useful answers.
*This doesn't directly answer your original claim that the software is good for SO specifically but cannot be widely applied. But, if what I suggest is true, then you would expect it to appear that way.
Take Wikipedia as an example. Community is necessary but it is not the goal. The goal is encyclopaedia making. Most online communities do not produce a wikipedia.
What this adds up to, in theory, is sacrificing some community building ability (more sites will dies from under participation)for more Q&A ability. While more of the remaining will produce a good archive of useful answers.
*This doesn't directly answer your original claim that the software is good for SO specifically but cannot be widely applied. But, if what I suggest is true, then you would expect it to appear that way.