People who do not ask correctly can be pointed to here http://www.catb.org/~esr/faqs/...
Often it is that they have no idea WHAT to ask. That can be solved by the above. It will show people who are willing to answer that the person asking has put some time and effort into it. Even saying "I looked for 'ABC + DEF' and found nothing" will show that it is not just somebody that is just somebody who wants the easy way out.
On part of the people who reply, I believe it is due to a lack of people who are active on forums. It is the same small group who replies and they will have seen all the standard questions 50 times at least and are tired of it.
Also what happens with me is that if I get an answer, I have no incentive to return to the forum, so I don't. That means that I won't give any answers, even if I would have them.
With Usenet I would have subscribed to the Newsgroup and I would have to unsubscribe from the group. Most likely I will stay subscribed for at least a day and read a bit. I might also read other things that come in. And perhaps I will then contribute to the general knowledge.
Not so with forums that I need to open and then try to follow what went on. I have tried, but it is just too messy to try to follow websites when comparing to Usenet.
And concerning the 'works for me' crowd. It becomes even harder when you have three parties involved. I had an issue with displaying Windowmaker correctly with the NVidea drover and running X. Each of them said it was not them and to ask the next guy.
Similar frustrations happened when I did bug reporting. Either no follow up or "It works here, please give more details." When you gave details, the answer was "It works here, try the latest version" Next a silence and "Please try the newest version, but install 25GB of extra software that will break your machine. And if you don't want to, there clearly is unwillingness on your side." So, yeah, I am not doing that anymore.