If your views are mainstream with those empowered to down vote and you tend towards noncontroversial opinions and "flow with the crowd" or can pretend to do so, HN probably is better than Reddit.
Although Reddit is a very low bar.
If you like your opinions strong and you think for yourself and you resent being signaled which way to respond and think, you'll be down voted and treated with condescending comments by those who like echo chambers of agreement.
"…you'll be down voted and treated with condescending comments by those who like echo chambers of agreement."
It's not the downvoting that's the problem it's that they often do so anonymously without comment. For example, as I've mentioned my post above stands at zero votes after oscillating as high as +3 (although it might have been higher without me knowing about it).
I believe in debate and if they disagree that's completely fine but I want them to explain why as by doing so things move forward. HN's system doesn't encourage that.
In this instance I neither know why they downvoted nor how many votes there were in total. In politics this matters. If say I get 3 votes for and 3 against it's reasonable to assume I've made a reasonably balanced commentent on a rather unimportant matter. If I get zero votes after 3k have voted for and 3k against then the matter is important to many but neither I—the poster— nor readers are adware of the fact.
FYI, my comment above typifies the issue. It currently stands at zero votes but I saw it as high as +3 not long after posting. It's anyone's guess how many voted for and against.
When votes oscillate around zero I take it that my comment is pretty neutral, essentially a statement of fact. Shooting the messenger is a well-known phenomenon.
Incidentally, something I've noted is that I'll often get downvoted days after the main activity stops. Vote stats therefore should be timestamped. It occurred to me HN could do an analysis of voters together with their actual posts. Anonymous stats like that could tell us much about why Social Media is in such a mess.