I was just addressing your question of “why” to people who use the placeholder. I don’t think it’s consciously used, I honestly don’t know how to create placeholder text other than the two ways I mentioned. I could see someone using it for a species that hadn’t been added to the database yet, but in that instance I would hope they would bump it up to genus with a note of the species name.
I don’t know if logistically it would work to add it to the notes section. What if someone had notes already, would it be able to add the text without overriding what the user had written?