Point about having a place for the good thoughts to congregate is spot-on. The question is, will HN grow to be unwieldy like reddit and slashdot did, or will something better come along without this one starting to suck first?
As an aside, I wish my handle here was "Anonymous Coward"...
"498. Hidden gems won’t stay hidden forever. Especially if you brag about them."
So yes, eventually HN will become like all the others, especially if the quality stays high. I am almost certain there is a 'Murphy's Law' type thing about this, though I don't know the name. Also, there will be another thing out there that does not suck while HN will start sucking, but it will be hard to find. Likely, there are a lot of them already, but their userbases are so tiny that it's almost impossible to find them.
Actually, hey. Why can't we engineer around this? Like say, have subreddits that your IP defaults into, keeping the userbases small no matter how big the site gets.
As an aside, I wish my handle here was "Anonymous Coward"...