> There's a difference in motivation between "check this interesting article out" and "please upvote me", but the ring-voting detector can't necessarily tell the difference.'

In the former case, why would they be linking to HN in the first place, instead of the article itself?

HN has a basic voting ring heuristic to ignore votes from direct links to HN submissions from a non-HN referrer for this reason.

I can't speak for other people, but personally, when I find a good article, I link to the source I found it through, rather than bypassing the source and linking directly to the article. (I don't do that when submitting stories to HN since HN considers that "blogspam", but personally I like finding new sources of good content, as well as sources of good discussion, rather than just the content itself. And in any case that's a heuristic for what to submit to HN rather than what to link to from elsewhere.)

At a minimum, I would tend to put something like this: interesting article (link to article) via HN (link to HN).

Though I'm certainly less likely to do that now that I know that HN does not like such links.

I don't think it's appropriate to post something like that about one's own story, but for a story you found interesting and want to share, I think it makes sense.