As others have noted, it's not true that "nobody is talking about game development" on Hacker News; however, I think you're correct it is not a dominant topic. I can't speak for other's interests, but I know for myself that although game development is something I find somewhat interesting, it is not something I pursue, for a couple of reasons.

First, I don't spend much time playing games, because they don't hold my attention long and they're not the best use of my time (they're a pastime, literally, a way to pass time, but I don't need many of those). I know you don't need to play games to make them, but a deep love of games probably helps motivate you to make them, and I don't have that.

Second, I'm ultimately interested in creating things that change people's lives to some extent, whether by helping them solve problems, communicate more effectively, earn more money, etc. I think many people on HN feel similarly - they are interested in building things that enable people to get more out of life, in some way, and games don't always fit that description.

Of course these are just my personal opinions.

I'm still somewhat interested in developing games but more as a way to improve my skills in other areas, such as Javascript (I'd probably focus on HTML5 games if I got around to it) and challenging stuff like AI.