While this account is only approaching its 2 year anniversary, I was a lurker for a while before that. I do agree there has been some decline, but my biggest complaint about the comments these days are the complaints about the decline of HN. They are all over the place and to me are a bigger annoyance than anything that the actual comments are complaining about (except for the community support comment - that needs improving).
Not meant to single you out - just my opinion on the overall sentiment on HN these days.
This account is 4+ years old and I was a lurker as well for a while before creating an account. I too have noticed a distinct decline in the quality of commentary over the years. It's not downvotes that are messing up the community; it's upvotes. The things that get upvoted more lately seem to be short quips or similar scoped posts. Maybe pg needs to experiment with removing the upvote feature from new accounts until they reach a threshold of x karma. If it wasn't for the 10 or 20 prolific posters here this community would be full of people with nothing to say but saying it loudly. I don't know if the removal of points from comments changed the environment for the better but I can only hope that it staved off the decline in community for a bit longer than inaction would have.
Edit: I think it's funny that the title of this post was changed to lobsters from its original title.
Not meant to single you out - just my opinion on the overall sentiment on HN these days.