Before: Provide communities and companies the software and hosting that enabled the creation of high-quality Q&A sites.
Now: Create a carefully cultivated garden of user-maintained Q&A sites with active communities and minimal overlap.
And that's fine of course, but it seems a little odd to judge the former was failing (after what, six months?) by using the goals of the second as a criteria for success.
A Q&A site is not a piece of legistlation; it's an entreneurial endeavour.
It's best to leave entrepreneurs to be free to create, experiment and adapt.
Stackexhange will miss out on some great sites by rejecting them before they even get a start. The best sites will be those where the founder/s constantly adapt the site to demands of the community, not those who have the best idea upfront.
But as you say, that's where the OSS optios come in. :)
And just look at how many crap blogs are on each of those platforms. Their goal is to curate quality content and the free-reign model has already proven itself to be incapable of it.