Sadly, you are probably right. For better or worse, I keep thinking that invite only forum is the way go to maintain a decent level of 'interesting conversations'. HN still has them, but it is getting harder to filter through.
I am constantly amazed at the thoughtful comments from people who are informed on a subject and take their time to layout a cogent argument. This makes it worthwhile to spend some time scanning more and more other stuff. I am getting to be quite a speed reader in this place.
HN will be just fine as long as Dang (and the other guy) spend so much energy here.
We also have our own form of Kryptonite, the HN front page list of discussions. Many of the people that get kicks stirring up trouble would not understand or care to read this stuff.