How many in the community are actually involved in bringing posts to the main page? I've a feeling most users only view and vote previously chosen posts, but I might be wrong.
I can obviously only speak for myself, but generally I agree with you. I come to that conclusion because up-votes are generally very concentrated on a few posts, rather than more evenly distributed. even though that that might be a result of the actual interestingness of an article, i highly doubt that it is so conform, especially considering that one out of very similar articles gets often picked out. even though it might in the end not represent the best source of information on that certain topic.
New posts are where you can participate in conversations. Posts on the frontpage are mostly done conversation wise. They are all talked out and you seldom get answers on your comment.
I view and vote on the 'new' posts page all the time. It's my favorite part of HN.