Your idea, thouhg nice, has a "big soft" problem! More often than not, the person who asks the question does not tag it "soft". Indeed, I have just checked the soft questios that are still alive on the main site, and I have realized that many of the nice ones haven't been originally tagged as a "soft" question. It seems that the "big list" questions suffer from the same problem; after all they become a "big list" after a while, and not immediatly!