I think it's natural, that people post less after some period of development.
I'll make a post in a strategy section elaborating on the concept.
To make an accent on the single most important reason for this: IMO the hand history format of poker discussion is insuficcent after a certain level of poker player's development. We need to discute the whole strategy, integrating the preflop and postflop play, and discussing not a single hand but a session.
One of the possible format is to post sessions of 100-1000 hands and analysing them. There are several obstacles to this idea. First, it requires much more effort from both the poster and readers. Second, many winning players wouldn't like to give away so much info by posting their entire strategy on the public forum.
P.S. As for begginners getting insuficcient help, I think they should mostly blame themselves. No one refused to answer a direct question, they could get rediculed a bit, but that's not too high a price for knowledge

. If you disagree with opinoin of a good player like Roy, Xas, Ice, etc., you probably should try to find out what is the reason for disagreement, because it's likely that that's you who doesn't understand some important concept. You shouldn't leave the subject, saying: 'Fine, we disagree'.