In that quote given by The Sandman

"have one and all entered at birth into the full enjoyment of their racial heritage. Their language, wisdom, manners, and the many graces of life that are theirs, are merely racial attributes which have been gradually acquired and accumulated in past centuries and handed down generation by generation, each generation adding its quotum to that which it received. "

I read the emphasis as being on the 'heritage'. I think the second sentence makes it clear that he was looking for culture that was handed down rather than suggesting that it was in the genes (or 'in the blood' as they would have said in his day). So tending not to collect from people with non-English surnames, or dark skin, may have made sense.

Multiple generations later society is more cosmopolitan and there has been over 100 years of access to recorded music, so that doesn't apply. It is far more possible for individuals to have grown up with, or absorbed, cultures that would have been foreign to their ancestors. And we use 'racial' in a different way.