"Generic" in this context has to do with replacing a specific topic with a larger, more general one that it perhaps has some connection to. The problem from an HN point of view is that it makes discussion less interesting and more flame-prone. The generic topics drown out the smaller ones the way a black hole will suck in everything that comes too close (https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...).
That doesn't mean the larger topic isn't important. Most probably it is very important, far more than the more specific topic is. That's not what HN is optimizing for, though (see https://hn.algolia.com/?dateRange=all&page=0&prefix=true&sor...). Trying to stay focused on the specific rather than the generic, and especially the inflammatory generic, is a big part of keeping HN intact for its particular purpose. Otherwise it would quickly become purely a current affairs site, which it's not.