Companies are for-profit organizations, even their claimed/actual love of diversity is driven by profit. So they are not going to pay more than then need to for any employee. They definitely use this to advantage against all employees. BATNA is an excellent way of thinking, and organizing your job searching in a way to give you strong alternatives can make a HUGE difference in pay for anyone. I have used it to great effect, and it seems so have you.

Real change will occur as each employee understands their real value and they demand it.