I think you’re getting downvoted because you’re reporting the typo in an odd and likely unproductive place.

I’m not sure what you expect HN readers to do about the typo. There is a comment section on the blog itself :)

It's not unusual that the author (or someone of the team) see the trafic peak an appears in HN to reply the questions.

Sure, that happens.

But instead of just reporting it directly, we instead get this unsubstantive comment (“Cool! Great! Btw you spelled a word wrong.”). Essentially just noise, nothing that provokes curiosity or interesting discussion.