Read "non-white", "non-straight", and/or "non-male" in place of "diversity" and you will see that it works 100% of the time.

I think you’re right. But that isn’t actually what diverse means. The opposite - lefty non-white, non-straight and mostly non-male people are a specific political group.

I think it’s quite on the nose for organisations to cater to that community explicitly. And the wider population is far more diverse than that.