i started getting downvoted a lot. since then, i've become much more of a lurker and have remained logged-out.
to me it's obvious, and necessarily the case, that the conversation happening is not representative of my views because i'm not sharing them. it's not worth it to me to contribute to the conversation, and get embroiled in an accidental dispute.
my views are my own, and i don't need to spend a lot of time sharing them at other people in order to live a satisfied life.
the internet, like the real world before it, is not my own space... and to the extent that i exist in it, i'm happier going my own way and not encountering lame-o jerks.
But even without voting mechanisms, nasty replies are just as bad or worse, so the general trend of chasing off the people who see things a little differently seems pretty universal to me.
In terms of fostering discussion, the comment voting is a silent killer.
Every once in a while I imagine something anxiety inducing about them, or catch a glimpse(and more often than not a positive one) in the automatic reply emails Reddit likes to send me. Sometimes I will look back at the thread, if I really want to know.
But I don't use these platforms to converse, even though I will happily make a reply to an existing thread. They are both too fast and too slow to be conversational. I use comment threads as a writing prompt instead, and by ignoring external feedback I don't experience pain from them, even though some of the time this might result in someone asking me something and never hearing a reply. If my idea is good, someone copies it and I see it in a later thread.