No offense but I think you've gotten lost in your thoughts and wrote down a response mid-conversation with yourself. Your "complaint" has been responded to already. The author finds it useful in the moment for himself, to better understand the topic. The author finds it useful in the future, to reference. Some other people may find it useful, and if you are not one of those people, no problem. If you haven't tried this method, it's likely you are overly skeptical of it. It seems like you have an extremely high bar for anything that deserves to be written down - only that which is new, original knowledge, not written down anywhere in the total extant written history of humanity. There is an argument to be made against spam but I think you're erring on the other side. I honestly suggest you in particular try this method. It will address your underlying concern of "rehashing" which we are doing, right now.