I'm sorry, I know that I'm reading a dead discussion. But your comment shows that you have no idea what impact The Descent of Man had. Both good and bad.

You can argue for or against it on many grounds, ranging from Darwin's sexism to the importance of treating humans as just another animal to its misuse by the eugenics movement culminating in the Nazi excesses.

But arguing against it because it did not impact the public position shows an ignorance of history.