So many posts sit on the front page with many upvotes and zero comments.
There's a weird mechanism that punishes posts with comments, because they are deemed "controversial".
Regarding downvoting - just disable it. What makes the echo chamber even worse is that only users with a certain amount of points are able to downvote. So people who have already avoided being downvoted by others get to effectively police who else amasses the required number of points to be able to downvote. It's a vicious cycle where only a group of like minded people will be able to downvote.