It wouldn't limit criticism of YC. A comment only needs a few people to endorse it to become visible. To suppress comments on any specific topic would require all the users with over 1000 karma to agree not to endorse them, which is hard to imagine.
Correction: it would require all users with over 1000 karma to read the comments of every post to HN. It seems like you are making the assumption that every user reads every post
Does a comment need to be seen by many users to be worthwhile? If it contributes to the discussion of a small group of users (who may not have over 1000 karma), is that not still valuable discussion that you would want to continue? I understand the goals of trying to promote healthy discussion, but I fear that this will have many unintended consequences.
It seems like a fallacy that if a comment isn't read and endorsed by users with over 1000 karma within a certain timeframe it will never be influential. Weren't most of the literary and artistic geniuses completely unappreciated by their contemporaries? We may not be a literary and artistic community, but I think the rule applies all the same.
Nonsense. Lots of conversations continue with an interested subgroup, especially new or niche topics. Its easily possible no one with 1000 karma will ever visit.
Which means such topics are dead to HN. What remains? Something we can't predict right now, but I suspect it won't be what we want.
I believe this is not hard to imagine at all. It's unlikely that all >1000 karma users will take the time to review every comment. So it'll be enough if the few users who happen to browse a thread have the same views on that particular topic.
