Gender and politics. I've noticed that it often doesn't matter _what_ alternative viewpoint you have, if it doesn't align with the predominant view of the thread (which, interestingly, isn't a single philosophy, I've seen multiple threads frontpage with different thrusts, e.g. recently during the tesla harassment discussions) you'll be silenced.

Someone can tell me if this is rose colored glasses or not, but I do feel that "Old HN' downvotes correlated far more directly with "does not contribute to discussion" whereas now it feels a lot more like a reddit style "support/oppose" voting contest.

What bothers me more, and has gotten me "in trouble" on a few occasions for speaking up in defense of hearing out, is that posters more fringe than myself, but who are still making a solid post and useful contribution, are often silenced/flagged into oblivion. It's not even a matter of feeling welcome or not, most people I find who post here regularly are _very_ polite/welcoming, but to watch silent attempts at forming an echo chamber gives me pause.

I agree with you completely. I always strive (doesn't mean I never slip up), to only downvote someone if they are not contributing to a discussion. One thing that irks me bad though is when people make emotional claims about complex topics without any references or even logical arguments to back up what they're saying. I really like hearing new opinions, but you cant have a real conversation when the other person is convinced they shouldnt have to convince you.

The most recent thing I changed my opinion on thanks to HN though was smoking - a guy came with studies in his comments, and convinced me there is actually a net monetary benefit govt healthcare systems have from smokers i.e. smokers die younger and the treatment method is shorter than other diseases. Those are the good moments on HN :)

I've definitely learned my lesson: Never respond with a political comment (unless of course it pertains to the thread.. though even that can get downvotes).

So politics and religion are two things I definitely stay away from on HN.