Within the tech industry, the correct proportion of minorities should be representative of your hiring pool (which is why I think they ask you to self report), or maybe even proportionally to "all qualified potential candidates", not sure how you'd measure that out.
The problem is even within qualified potential candidates, many minorities are still under-represented. This is a societal problem outside of the tech industry, but one that leaks into it.
More opportunities for these minorities to get a leg up to enter the field would bring the proportions closer to normal, stuff like affirmative action for schools.
It's a tough answer and nobody wants anyone in the chain to take responsibility for lifting up those that have been put down, it's definitely a flawed approach but I'm glad to see businesses attempt it.