Here is a good example post from when I asked in this thread if they had seen the guide, FAQ, or tour. This is one of the scenarios that is pretty common and is the reason why I think having a one-time tutorial at the beginning may not be enough if users aren’t going to use the site seriously right away. It’s a good example of why we shouldn’t just write it off as people being stupid.
This post by @koichi actually sounded like a reasonable idea, although I’m not sure something like this would be possible. I do think that something that something that is front-and-center would be the best. We need something that could quickly get out of the way for active users, but that might come back for users who sign up, but don’t use the site until after a long time. Ironically, SRS might be the solution to that.