What traffic are you getting back from commenting on HN. If you're not getting any, why are you wasting your time? Of course you can post online for other reasons, like participating in a debate, building a community, working on a project, or just for hobby. And usually that's the good part of the web. Otherwise why would people be using site:reddit.com in their searches.
Getting on HN doesn't cost me a dime though, aside from spending personal time. Having a web site costs money both to maintain the hardware, and the content. And if someone wants to index the content he should give me back traffic. That's the premise upon which search engines were build. You break that, we end-up with a walled off garden that handles all the information.
