The other thing that keeps downvoting from being too frequent is the karma-dependent ability to flag questionable posts that may violate the guidelines.
"Please don't submit comments complaining that a submission is inappropriate for the site. If you think something is spam or egregiously offtopic, you can flag it by going to its page and clicking on the "flag" link. (Not all users will see this; there is a karma threshold.) If you flag something, please don't also comment that you did."
http://ycombinator.com/newsguidelines.html
Flagging evidently does draw the attention of some "supermoderators" to the post, and they deal with it according to community standards they have agreed to. That's enough for me.
In general, I say "Good job!" to the people who run this site, who are thinking carefully about how to get both the technical and cultural issues right. Inasmuch as they don't seem to desire to expand the scope of discussion here beyond HACKER news
"On-Topic: Anything that good hackers would find interesting. That includes more than hacking and startups. If you had to reduce it to a sentence, the answer might be: anything that gratifies one's intellectual curiosity.
"Off-Topic: Most stories about politics, or crime, or sports, unless they're evidence of some interesting new phenomenon. Videos of pratfalls or disasters, or cute animal pictures. If they'd cover it on TV news, it's probably off-topic."
it seems to me that some entrepreneurs could attempt to transfer some of the technology and some of the culture, with appropriate permissions and credit of course, to sites with discussion of other issues. That would be lighting a candle against the current darkness of much online discussion.