That's ludicrous. If I hire only from Harvard, but then I start hiring from state schools as well, the employee racial composition is highly likely to change.
The axiom presented is that the employee composition must mirror the surrounding social composition, ergo you are hiring for racial reasons because you must set quotas and then hire based upon satisfying (and not exceeding) those quotas.
As an example, if the social composition is composed of 40% Earthlings, 30% Martians, 20% Venusians, and 10% Mercurians and your workforce consists of 10 men: You cannot ever hire more than 4 Earthlings or 3 Martians or 2 Venusians or 1 Mercurian and must refuse or terminate any excess. If you cannot hire even 1 Mercurian at all you arguably can't hire anyone.
That's racist.
But the idea of quotas is something you pulled out of nowhere. It was not part of the conversation until you showed up.
It's a strawman.
Also the post up above was talking about statistics with error bars a thousand people wide. The idea of having a demographic match with 10 employees is... also a strawman.
In any case, none of that takes away from the crux of this conversation that programmes like mirroring surrounding demographics and others are discriminatory and have no place in free and civilized societies today.