others will simply spew vitriol your way

I'm going to have to disagree here, that's much more helpful to a person than wordless shunning. Like, regardless of how unhelpful it can be, it is a factor of infinity more helpful and more humane than just downvoting. As Eliezer puts it, apathy is sometimes worse than hate. At least someone who hates you cares enough to do something.

I actually think the setup we've got here where you hemorrhage karma every time you engage a downvoted thread is a really obscenely terrible choice for a community of analyticals. A norm of rejecting arguments without feeling any need to explain yourself is much worse for us than a relatively weak time-sync(next to the average mobile game, comment trolls are nothing). In the least, the threshold (-5 karma) is too low.