It's a complex issue for sure. At the company level, I don't buy the "won't understand our customers" much. And, while we shouldn't tolerate negative hiring discrimination, there is little joy in having incompetent coworkers of any color. And, yes, there are cultural problems within some minorities.
But, at a larger scale, once your country has sizeable minorities, it is in everyone's long term interest that large segments of the population are capable to fully participate in economic opportunities. If that doesn't happen everyone else gets stuck with societal unrest, possibly criminal activity and welfare bills.
So _some_ nudging from the pure meritocracy path can be warranted. Even from the perspective of a white taxpayer.
Call me an optimist, but I believe success breeds success. Once some members of an ethnic group succeed, their status can motivate others to follow. The reverse effect is, IMHO, responsible for a lot of underperformance - if all your buds are on the dole easy to blame the dominant group and retreat on yourself.
In many cases, there a mix of some negative discrimination by the majority coupled with a culture of non-participation by the minority. Complex to break this kind of fail, but doesn't mean we shouldn't try.
I'll add that I also consider it the decent thing to do. But there are cold hearted reasons to do it anyway.
Last, and cynically, in our age of Internet outrage, a company may find it in its best interest to at least appear motivated to diversity. So why not try to do a good job if you're stuck doing it anyway? As long as you don't just hire underqualified folk.