Probably because old folks know that mermaids are a myth and don’t identify as mermaids ( although ai think I saw a docuseries about a 30ish year old thinking he was one) Where as furries bleed the line between what might be fetish realm, and what might be some people actually believing/thinking they are a furry animal–which would be considered a delusion.
It just checks to see if there is anything in a bash.d folder, if there isn’t it moves on. Just somebody being preemptively helpful to check for other locations