why focus on parents? People who became parents have supposedly already reached a baseline of stability and security (otherwise they wouldn't have the resources to have children). There are plenty others who are struggling without a partner (or children).
https://wtfhappenedin1971.com/
Unfortunately, this disproportionately discourages the most responsible people, with the best long term planning, from reproducing.
(At least, among those who are financially struggling. You could also argue that those who can't get out of poverty don't deserve to reproduce (and many in those think tanks appear to share similar views), but (1) that's reprehensible and (2) it doesn't work anyway since there's always a subset that just doesn't care and reproduces anyway.)
"Supposedly" is doing an awful lot of heavy lifting in that sentence, as is your parenthetical note.
And we're focusing on parents because this article is about melatonin use in children.