I vote against this (and this is coming from some one who believes HN contains a lot of shills)

Bots are recognizable and can be selectively ignored. But an echo chamber that would result from measures like this cannot be, because you cannot see the potential comments and posts that were snuffed because some one didn't bother.

If you want HN to be a place to feel comfortable and your world view to be unchallenged, sure, go ahead. But then we already have reddit.