Such a site will never fit within the scope of Stack Exchange's style and mission. Furthermore, closed question messages are not the place to promote an Area51 proposal. Can you imagine if you were a brand new user, just asked your question, and were immediately told "oh, sorry, you can't ask that, but if you want you can get involved in a lengthy process unlikely to be successful in attempting to create a site that might someday accept your question"? Not user friendly.