Suppose you we're in charge of a q&a site whose quality was going downhill. How would you go about fixing it if not for locking and deleting questions?
Some people have an intuition that the presence of these historical bits contributes to a reduction in quality. I think that intuition is mistaken. Who knows who is right or even if that's a meaningful thing to ask. We're just discussing preferences.
The mob is always happy to stoop to lower levels of discourse. It cannot be trusted to govern itself as a site grows. And most of the Internet is more than willing to cater to this out of fear of losing visitors. I say bravo. Let the 'gregarious' go elsewhere and live in the land of forum signatures, endless bike shedding, and editor wars once again.
The only questions on SO are the trivial questions that could be answered by reading some documentation. If questions are broad or open ended, the value lies in the discussion, not in any particular answer. I also found that many accepted answers are blatantly wrong. For me, SO has no value. /r/programming doesn't have any value either, but that doesn't make SO better.
There is a huge opportunity for a quality, ruthlessly moderated programming-centric discussion site. I'd argue that an aggregator is suboptimal over the long term due to the economic structure of the Internet favoring eyeballs over quality content.
I do agree that SO quality sucks at times, though.
I really think moderation is the best choice.
Yogi Berra described the situation as "Nobody goes there anymore. Its too crowded".