Because to those who champion diversity, an understanding of what it is, is as unobtainable as the thing itself.
The nature of being lost is an inability to know where you are. Such people have never, and will never, have any idea where they are, what they are, who they are, or why they are.
It panics them to imagine everybody is just like them.
While at the same time, it panics them to imagine anybody isn't.