I wonder. Considering it would be easy for HN maintainer to implement this feature I came to the conclusion they considered it and chose not to go with it. Maybe because that would somehow degrade the HN experience. Maybe that would shape a `quick-reply-on-the-spot' tendency instead of people getting back to the comments a few hours later to check out if the conversation brought new insights. A mean to keep some kind of posters from over posting.
The most addictive notification is "someone replied to you"... you want to see what it is, and then you often wind up replying.
So it will lead to more replies from people acting on impulse and arguing.
When you agree with something, you share it. When you disagree, you comment. So thus we can measure how popular and controversial something is by how many shares and comments it has (horizontal and vertical).
I think the way reddit does it is great. A red number in the header if you have replies and then an unread page where you can see them and click for context.
That's funny. The reason I comment here more than Reddit is because I get no notifications. On Reddit I click `disable Inbox replies` as much as possible, but sometimes forget. I like being able to look at my comments when I want to reply.
If you don't mind losing private messages (I get ~0 of those), presumably you could add the reddit mail icon to your adblocker or something?
For me though, notifications are much more important on reddit than here. Here I can see replies directly on my user page (and replies to them, which I also like to follow), there I'd have to click through to each of my recent comments to check.
I think it would also really help to have some kind of notification in the HN header.