It is interesting because SMART being "niche jargon term" is very dependent of the audience. Nowhere the author needs to assume that the post will be posted on HN where the audience is probably larger than the originally intended one.

In many places NixOS is a niche jargon term.

Also, in the first paragraph of the article there is a direct link to smartd that has a clear explanation for what smart is, no need to Google.