Shaddows - 3:42 pm on Aug 23, 2012 (gmt 0)
seem to me that it's downright insane that a publisher should have to spend time removing noindex tags manually (which would be impossible in the case of hitchhiker's site), or waste server resources to do it automatically. If Google doesn't think a page is going to help a searcher find an answer, it shouldn't be as highly ranked
Google wants to serve the searcher. It does not have infinite resources. If your site is an unsatisfactory destination on too many occasions, Google may well decide to score your whole domain a little lower.
So it's up to you. Self-manage, or let Google make the decision for you.