In case of some insist not implementing the idea, the natural selection will make the firm less competitive.
If 'some' is a minority, then maybe. But what if 'some' is all? If we are talking about an inequality of opportunity that is embedded within society, then 'some' is likely to be either
all or
very nearly all.
If the most talented football player in the country is black, but every football team only hires white players, then no team is at a disadvantage.
If my company has all white men employees, I'd fire my HR manager since he/she clearly doesn't do the job. IQ-wise, at least there must be a bunch of Asian in my company.
You want someone who can do the job at a minimum of '100%' ability level. The best white male candidate can do 105%. The black female candidate can do the job at 108%. The HR manager has hired the white male at 105%, he's hired someone who is more than qualified to do the job well... he can't really be fired for that.