Posting it here helps accumulating other people upvotes, which, presumably, Dan and Nick can see on their end. It also opens subject to a wider discussion, which is hardly a bad thing. Meta threads are pretty damn useful if you ask me.
I agree, and I actually like the meta-threads, but I've had much more success talking to Dan privately than I have in trying to motivate changes with public comments. I think if you're really serious about a suggestion, mailing Dan is the right way to go.
If there's one consistent thing I've read from Dan in his tenure of publicly moderating the site, it's "please mail hn@ycombinator.com about this stuff". I'm just heading him off here. :)
