I used to be pretty active on SO and Programmers.SE as a young buck, and back when SO was still pretty new and shiny. Nowadays it just feels like a race to the bottom as someone trying to answer a question. The winning strategy is to post a shitty, incomplete answer and get the upvotes and while that is happening, update to a better, clearer answer, oftentimes poaching content from the guy or gal who took the time to do a detailed, "good" answer. I get the notion of consolidating the answers into that one perfect answer, but working on a good answer and having it poached by the highest voted answer will leave a bad taste in most folks' mouths.
In the case of Programmers.SE, there was a shift in the site topic and, in my opinion, some rather overzealous moderators along with the handful of folks who just seem to sit on the site and close-vote any and everything that does not perfectly align. Always be wary of those that seek power over their fellow man...
StackOverflow and the surrounding sites are a good force overall, don't get me wrong, but as someone who tried to be active and use the site, it leaves a lot to be desired. I'm not interested in answering "How do I do X in jQuery" and I'm not interested in having someone plagiarize me.
That's true, if you care about the points, badges, etc.
Jeff Atwood has discussed this subject fairly extensively, and it does matter to a lot of people, which helps make SO more successful than it would otherwise be.
Could you build an incentive strategy and reputation system around collaborative answers?
While I don't argue the demonstrated knowledge and skills, having talked to job recruiters, SO is actually very far down their list to my surprise.
So if you are getting discussion, you are actually just experiencing the common case of getting your needs addressed before the terrible moderation kicks in and closes good content.
Also confusing from the point of view of the site operators - aren't they missing a lot of site interaction and pageviews and additional free content, etc. ?
That's not very smart. Sometimes, even a technical problem's context can be complicated enough to merit several different "good" answers, depending on other factors.
Maybe someone should formulate a law -- over time, any site's moderation starts to suck. There are factors involved with this, such as depletion of low-hanging fruit, popularity drawing more attention from spammers, and increasing workload of moderators.
It happens quite often that I look up something that I already have (or could write) correct working code for. It's when I notice that there's more than one way to write that code, and I want to do it the "right" way the first time, so the decision doesn't come back later and bite me, when I go out looking for what is considered "best practices" in such a situation.
Usually there's more than a few "correct" answers to what is considered the best practice, and the choice depends on the context of your problem. That is when the discussion is invaluable, without it I cannot determine which of the choices apply to my problem.
But of course it's your fair right to say "well okay, but SO is not intended for that".
I hate to be contrarian, but I have not experienced much of the negatives people are complaining about here. StackOverflow has been a fantastic resource in my programming career.