Dear greatnan I hardly ever get involved in these sort of threads. However, going back to your OP - perhaps the answer is patently obvious: we are not all the "presumably mature" people that you hope would post on a serious thread. I know I can sometimes be hopelessly immature, impulsive, spontaneous, make mistakes etcetera.
The most important thing to me is that we are not all the same, thank goodness, how boring would that be. If someone witters on a serious thread, I ignore it and pick out the bits I want to read.
Witter or not, there is always something to learn from most of the people who take the time to post on these forums.