Hi mike_tan, I didn't realize there was already some discussion with you here. Two major points:

1. This does get discussed from time to time. Here is a post from the creator of the site, and a long discussion where members of the site hash things out. https://news.ycombinator.com/item?id=459289

2. Everyone knows that "flags" are more powerful than upvotes, and therefore they only flag things that they really think shouldn't be on this site. Flags are not used as downvotes.

Some users can still see "dead" submissions. Go to your preferences and turn on "showdead" to see auto-killed spam submissions, comments from known trolls, etc.