I have a theory as to why leftists began identifying as "they/them nonbinary." Could it have anything to do with worshiping the state and identifying with it as your parent and later attempting to emulate it by "becoming" a wretched manmade beast? The state has no gender, and it is not an individual, it is a corporation of many individuals in a hierarchy. Therefore a "they/them" sees themselves as a corporation, or a fictional entity, or a beast, rather than a single being made in the image of God.
In the Bible, people who are possessed usually talk in the plural. I am starting to believe that is where it comes from.