It's got to be both more newsworthy and also more interesting than some random Techcrunch headline if you're even a casual chess player, and I won't even start on Wikipedia links, etc.
I'd also like to see more Go articles.
1. The fact that Anand won. Anand instead of Topolov, okay, how is this fact intellectually engaging to me unless I'm a fan of one or the other?
2. The game itself. What's interesting about this game except the fact that it's played waaaaaaay above my skill level, and therefore represents an opportunity to learn? There are craploads of those games out there. You can get a subscription to Chess Life and get dozens of grandmaster games every month. Except for players who are very unusually skilled, this game is not any more interesting or engaging than any of the thousands of games played every year between lower-level grandmasters. Those rare players (certainly at least expert level; anyone under expert level who thinks they can learn more from Anand's moves than they can from a random International Master is fooling themselves) are already following this news on chess sites.
So, to sum up, everyone for whom this article has special interest will see it elsewhere. Nobody who will only see it here can tell the difference between this game and the thousands of other grandmaster games played every year.
I don't think your logic corresponds to the actual community preference when it comes to putting things on the front page. There are a huge amount of general interest articles devoted to things that everyone will see elsewhere. It's because people like having one-stop shopping for recent news and because people value the HN comment threads on news items. (I did go and spend a few minutes examining the portion of the game that they're discussing above, and I'm the better for it, I suppose.)
Look, I'm with you if think that we should only have really fascinating content that people are unlikely to find on their own, like some awesome technical Metafilter. I would love a site like that. Go make one. On the HN front page is an article about today's Senate vote on the Sanders amendment; the same "1000 true fans" article we've all seen ten times for two years; an obituary for Frank Frazetta from the NYT; assorted press releases from small companies; a repost from Reddit about Facebook FUD. (To be fair, there are some good posts, too.) So that's not what we have. We have general interest articles about all kinds of vaguely newsworthy things with OK commentary. Hell, we frequently have the very same articles posted month after month. On that scale, I think this weighs in above average.