A valid reason to kill this one. But there seems to be the problem that controversial storys get flagged of the frontpage very fast, which then makes other people repost them. Probably because the story is relevant to them/they want to discuss it.

In addition to this, there seems to be a heavy penalty for posts that get more comments than upvotes, which sometimes kills quite inspiring discussions.

How about introducing a "controversial" tag that gets added on posts with lots of comments and flags and having a setting (similar to showdead) to make them invisible for people who don't like to discuss. This would also solve a part of the repost problem and the "censorship" accusations hn sometimes gets.