Or perhaps the declaration is actually this: "There should only be maples and oaks! I hate all the other trees because I don't understand them and they seem weird to me and when I was growing up there were only maples and oaks in my yard, so let's only have maples and oaks."

There are no such thing as pines or catalpas or birches or spruces or poplars or coconut trees or palms or walnuts or elms or willows or baobabs or redwoods or any of them! They are just trying to groom the maples and oaks to pretend to be not maples or oaks!"

Claiming there are only two genders is like saying, "I declare that only maples and oaks are trees! All the other tree-like things out there are just faking it and are actually either oaks or maples!