Because people reading the comments, who like the concept, may find it useful. I agree it feels tacky, but on the other hand as a reader, I prefer knowing abou

Because people reading the comments, who like the concept, may find it useful. I agree it feels tacky, but on the other hand as a reader, I prefer knowing about alternatives. The other thing -- and it doesn't apply in this specific case -- is that often knowing about competitors helps clarify what's unique about the original linked post. It's a thing I see on HN a lot: Marko got posted, somewhat says it looks like Svelte syntax, then somebody replies to that and says the Marko is much more performant.