That argument is frequently made to deny the existence of any form of discrimination. Note that it would have applied to say, black people in the 1950s in the USA.
Except one thing, you where likely to get into trouble if you had a black man hired to do what would have been considered a white mans job, so the black guy was strictly speaking not worth the same as a white man because he would (in directly, but pretty certainly) cause you problems with your customer.
That is not true today in Silicon Wally, because nobody knows who wrote the code one is currently using.
