It is a simple fact that very few people are following updates on the wiki, and in any case it's less convenient to have a discussion over there. Moving the discussion to LW is a practical matter, a way of drawing more attention and feedback from the community.

The wiki reflects views which have attained a high degree of consensus. Not complete consensus because yes then it would be empty. This is just because we're such a bunch of argumentative contrarians.

If it helps, think of putting Eliezer in charge as a sort of Schelling point. We need some form of minimal authority structure, it might as well be the founder of the website.