A noble and well made point, only that you are confusing the terms "race" and "species".
Inter species diversity exists between species while intra species diversity exists within a particular species.
Racial distinctions don't exist outside the human species, so they are a form of intra species diversity.
But as you point out, species may not cross breed wihout scientific intervention, (and if they do their offspring are sterile), whereas there is no barrier to procreation between different races.
We are all human.
And all different.
My daughter and I are apparently both white, but I have taught her to respect differences between people by showing her that her skin and mine are very different in colour.
When I hold may arm up against hers, she can see for herself that we are different. And I then point out to her that everyone is different to everyone else.
So she has no illusions of "them" and "us" - she has an idea of a world full of individual humaans with an equal right to exist and pursue happiness.
Next time you are in the company of another person of the same colour as you, put your hands next to theirs and observe the differences.