I'm not sure if you're aware, but GitLab has integrated CI available on gitlab.com, which is a like-for-like alternative to CircleCI - so in that sense this comment is very much on topic, in my opinion.
HN isn't but the place I'd expect to be downvoted for a factual statement. I have seen the comment before and it feels like someone trying to plug their service the moment "CI" comes up.
I know Gitlab is HN's darling but to me it's not reasonable to plug your service every time a competing service is mentioned.