Great phrasing.I think you should see this as "portfolio diversification". The market (world) contains different sectors, industries, market caps, etc. (genders, ethnicities, wealth, cultures, etc.) and you want your portfolio to be diversified to represent the market properly so that you get the best of everything (different opinions).
I don't think that if you want different opinions, you should get people with different opinions and not settle for race/gender as proxies for those opinions.
I think not only is using race or gender as a proxy for different opinions technically wrong, particularly at the individual level. To presume so is racist and sexist.
Thinking that a particular group (race or gender) has a certain opinion, or acts in a certain way is discriminatory.
Also since it's well documented that intragroup scatter of most personal characteristics (ie intelligence, political perspective, philosophies etc) is significantly larger than the mean difference between groups, it isn't likely to provide the diversity in those characteristics you want anyway.
In short, I don't think discriminating based on race and gender is in any way a sound business strategy.
The basis that it will provide diversity of opinion is itself racist and sexist.