The point of a diversity statement for the candidate to ruminate on their teaching practices with respect to a diverse classroom, which is a fact of the job rather than a political or ideological matter.
Most people in the course of their job do not closely work with people of diverse backgrounds. People who work at universities will work with people of all backgrounds and abilities. It’s not just about race or gender, but language, mobility, mental disabilities, and so forth. People in roles that deal with so many diverse people need to be able to articulate how in a statement. That’s not unreasonable or political, but just a reality of the job.