Tony Sidaway wrote
I know how it works. I'm suggesting that articles of no interest to anyone
except the author (and I don't happen to think the example given comes anywhere near qualifying for that particular condition) probably shouldn't be FAs.
But aren't you trying to make your point, by a confusion of two senses of 'interested'? If there wasn't the fact that people can be interested in articles (sense 1), in the sense of appreciating the content, without being interested (sense 2), being prepared to author them at least in part, WP would be a different animal. Wikipedians support those who are not simply doing work they might have done themselves, given time. So, a single-author article can perfectly well be suitable for FA. (If this is not relevant to what you were saying, in some way, perhaps this thread is straying off topic.).
Charles