Hmm... more specialized fora will have the more concentrated focus of intentionally-informed people who've gathered explicitly to discuss a topic. Too much off-topic noise will get you shunned, because people come there for the signal (Reddit, though I love it, is noise incarnate). With far fewer threads, people maintain a discussion rather than post and run. In far smaller communities, with active posters within Dunbar's number[0], will call you out on your shit or for bailing whenever you get shut down.
