If I am asked a question that I didn't answer in the ad - if it is one that I have reason to expect will be asked again, at least - I edit my ad to include the info.
Perhaps the crux of your argument is that you believe a majority of the posts in the classifieds to be helpful questions and responses.....if that was the case, we wouldn't be doing this now. Those posts were far overshadowed by fluff and attaboy posts (harmless enough, and certainly friendly; but they are bumps, and they get in the way - heck, I've gotten complaints because people were scrolling through 5 pages plus of that crap trying to see if something had been asked/answered before posting it). I won't say that legitimate and helpful questions were less common than (malicious) disruptive posts...but I wouldn't be surprised to find that it was pretty close; or that on any given day, the scale was tipped toward the disruptive side. (disruptive didn't necessarily have to be the interpersonal hostility that showed up when certain people posted ads - I'd consider the sarcastic pricing comments, directing people toward other sellers, etc to be included).
Perhaps the part of the negative response is because some people look only at a section or two in the classifieds, so they don't see this as a widespread problem
