Political debates where there's a right way to think, or the downvotes grey out your post.
Downvotes for factual data that is inconvenient according to what the people who hang out here too much think is "true."
The same debates come up time and again, never resolved.
Are you becoming Reddit, HN?
You need to give more of a voice to the thinkers, and less to the people who are using the internet as a TV substitute and/or ersatz psychological care.