I think there's a couple things.
There are bots, like a program that goes around the internet looking at sites, and spammers make profiles some times too. So not all the people are people.
After that it's just a matter of whether somebody's in here reading and learning, but not interested in posting. Or they just figure somebody that knows more will do it. I can see how less, better advice is more helpful. Especially in the new reefer section. There was a thread a week or so ago about how new people should shut up and let pros answer questions in here.
I'm not sure about all that, it doesn't seem necessary for sk8r to personally respond to every "omg my ph is .01 too low, how much buffer should I add!!!1!" thread. Also, that thread made me think people might feel unwelcome. But at the end of the day this section is for helping noobs reef, and people with a lot of experience helping them are very good at explaining things with enough info to be clear, but not going on tangents or overwhelming folks. It does get kinda messy when a lot of people chime in with crackpot solutions to a simple problem. Like, ugh the ich threads can be insufferable.