When I see a Jackpost, I'm more inclined to go for the eyes. Although reaching for the jugular is effective, there is the matter of delayed relief.
I agree with most of your post. However, imo you do too much injustice to using this site or any other site for the very purpose you state of keeping a journal (same thing, different words), albeit a very special journal in that it allows for feedback. To me, an internet site like ET is an autobiographical tool mostly to write down my thinking at any moment. I expect nothing more for myself. If I am able, I help out another if I know the answer, otherwise I give my opinion and state it as such. If I am real lucky, an internet site can be a source of income in the form of some gracious person leading me in the right direction and there have been many of those, or perhaps a source of friends, and I have met some on ET. I would say after food/water, shelter, sex, one of the most basic human needs is the need to be creative. Why do you think there is a mass exodus from newspapers and tv media in general towards the internet? I forget what the technical term for it is, but the idea of a site is that it allows for participatory creation of intellectual content, without having a talking head just read a teleprompter and spoon feed you information. Posting is creative instead of consumptive. When I post something, I expect nothing because it is mostly my psychology turned outward. However, I am delighted if someone can take my initial post, and lead to a discussion and interchange that will allow for both or many to cooperate in the creation of interesting content.
Thank you for your thoughtful response, well put. ET as diary, anonymous confidante, sphere of psychological projection, venue for making new friends of like mind (my take on what you put more eloquently). I would only add one thing. To your list of needs. To get wasted periodically.