I sympathize with your points. I think the unfortunate answer is that either forums are open or they are not. Freedom is a messy thing. I do not think there is a thing you have suggested I would disagree with. I would hope all would think like you do. But in this world it is not true. There are a great many opinions, some better than others, and no universal judgement. Some come to these forums to ask questions, some come to learn, some come for entrainment, others to entertain (be it themselves, their friends, or the community at large). Some, honestly, come to be disruptive and build their own self image or tear down others. While I can suggest these are potential motives, I cannot suggest the motive for any particular person. Only they know that.
I believe any forum of open and free communication will evolve/devolve based on those who participate and those who are rewarded. Spoken (or written) words have no value. Words that are heard (or read) do.
Open and free communication is not always the best course of action, though I would hate to see a world where it was typically not an option. To me it appears these forums are more about a social network loosely contrived on sharing information and a place to seek advice about Second Life. One should question why this particular forum must even exist. The same can be asked of the LSL Wiki. They both share an important component. Linden Labs does not provide the answers that their customers ask and require. They often do not even provide the basic information to be able to discover the correct answer. Instead, they have provided a open town square, with occasional authority, for people to try to resolve these questions for themselves. I guess, as it is a "game," finding the answers might be considered part of the game play.
I should note also, you even get points for the number of times you post here. There certainly must be some people who view that the goal of the game of forums is to get the highest number possible. That is game theory, after all
In the end, we all will vote with our browsers. Either we view (and possibly participate with) what goes on here or we don't. Personally, I think I may have voted wrong.