An interesting point I'm noticing is that almost every time I start to get downvoted for something that is correct and I am able to edit my post to ask why I'm getting downvoted I have observed that:

On HN: my original comment is almost always resurrected and eventually positive upvotes.

On Reddit: my original comment is buried even faster.

I should test using some controls (maybe post something incorrect) to see if the trend continues. My hypothesis is that HN is just a smaller, more niche and possibly better education group due to the content versus reddit.