Pretty pedantic. I think we can agree that since the title and parent comment mention "Spartans", they are talking about the Spartans and not other residents.
[1] Source: https://acoup.blog/2019/08/16/collections-this-isnt-sparta-p...
I would suggest reading the posted blog-post. The author <em>do</em> know what he is talking about and–in my opinion—quiet an engaging writer.
"Σπαρτιάτης" is used in Greek (modern and ancient) to mean a (male) inhabitant of a place called "Sparta". What the blog author claims is that there are _two_ words, one of which means free citizens of Sparta and the other, helots. He says that one of those words is "Spartiate" and that the other is "Spartan".
This is a distinction that is impossible to make with a single word in Greek. The words he uses, "Spartan" and "Spartiate" are two Latin transliterations of the single Greek word "Σπαρτιάτης", that has one single meaning, as I explain it above.
Furthermore, the distinction between free and enslaved inhabitans of Sparta is, in all historical sources, made clear by using two words with different roots: "Spartan" for the free citizens of the city, "helot" for the enslaved people of the surrounding territories of the city-state. Nobody else than the author calls one "Spartan" and the other "Spartiate". That's entirely the blog author's made-up terminology.
So what I'm saying the blog author has made up is the distinct meaning of "Spartan" and "Spartiate". I do not claim that he has made up the word "Spartiate", as you seem to assume in your comment. Please correct me if I misunderstood your comment, and not you mine.
And a small edit: It was your last parenthesis that confused me, I would have written it as:
“or even "Spartiate", a term distinguished by the author of the blog as distinct from "Spartan"…”
"Homoioi" (όμοιοι) means "equals" or "peers". That's what Spartans considered each other and they'd use that word in context, but used the demonym "Spartan" to refer to their fellow free citizens of Sparta as did everybody else. The helots were called either helots or ..."the Spartans' slaves".
And as for the title point: Spartans seem to only be mentioned in the article coverage of the research. They are not the topic of the research itself. Sparta doesn't even appear in the abstract of the paper. Demonstrating that infanticide of disabled babies wasn't a widespread practice in Ancient Greece does not necessarily mean that it wasn't practiced by a group that only consisted of the elite class of one state.