I’ve been using HN for a few years now, mostly lurking but commenting every now and then, and I’m creeping up to the downvote privilege threshold. (I think it’s 500, not 400.) I wouldn’t describe myself as “someone who says lots of things other people like to upvote,” I think it’s more “someone who says little things over many years and some people have upvoted them here and there.” In other words, for what it’s worth, I don’t think that your description of HN matches everyone’s experience, and not everyone with downvote ability is the same type of person.