Ultimately, both of those commenters are annoying. Saying "I use Arch btw" is a useless self-serving statement that provides no benefit or information to the audience. But engaging with that message in the manner displayed is also pointless and stupid, even if the statement is correct.
The saving grace for the "Linux user" commenter is that they are self aware about being annoying, judging by their last comment. So hopefully they were just being ironic. Or rage baiting.

I use(d) Arch, btw.