You can read it in context here.
I'm not sure what difference the context makes. If humans are merely animals, then killing humans because they do not have the desired breeding qualities will be acceptable. Deciding which human animals can and should breed will also be acceptable. Is taking Hitler's core ideas and moving forward with them, putting a more presentable face on them, ok? What if someone without a silly small moustache was the face of eugenics? What that be ok?
Is reducing humans to the same status as animals, in a world where animals are bred, farmed, killed and used as 'machines', a good thing? Didn't it lead to serious issues previously, such as "ethnic cleansing"?
People are welcome to think that eugenics is a good thing and that social Darwinism should be explored and developed.
I don't happen to agree.
I don't think it's ever acceptable to reduce humans to mere animals.
I wonder whether, some 60 years after Hitler's death, we might at least venture to ask what the moral difference is between breeding for musical ability and forcing a child to take music lessons. Or why it is acceptable to train fast runners and high jumpers but not to breed them. I can think of some answers, and they are good ones, which would probably end up persuading me. But hasn't the time come when we should stop being frightened even to put the question?
Notice the use of "moral difference". Was what Hitler tried to accomplish moral or immoral? Or did he just balls it all up for the eugenicists by proving to be too extreme? Should human animals be more gently moved into selective bredding rather than pushed into it with a cattle prod the way Hitler did?
Dawkins isn't afraid to ask the questions that Hitler ballsed up and made politically incorrect. I personally believe that reducing humans to mere breeding commodities (or animals) is immoral.