People will often judge unintelligent assertions uncritically if their source is someone regarded as intelligent.
In other words:
What was so bad is not that Kipling said that East and West would never meet, but that so many people took this ridiculous assertion so seriously because it was written by Kipling, and Kipling had a Nobel Prize.
What was so bad was not Pauling's advocacy of megadoses of vitamins, but that so many people took this ridiculous advice so seriously, because Pauling had 2 Nobel Prizes.
What is so bad is not Hawking's ridiculous fear of artificial intelligence, but that so many people assume that there's nothing ridiculous about it, because, Hey -- it's Hawking.
People, even very bright people, make mistakes fairly often. It's referred to as being human. I'm not so much concerned about the mistakes listed above committed by Kipling, Pauling and Hawking. I'd put those under the "everybody's human" category.
What bothers me here is the widespread uncritical acceptance of bad ideas expressed by intellectual authorities.
Nietzsche was bright enough to see that it's wrong to accept what anyone says uncritically. And unlike many other intellectuals -- his one-time friend Richard Wagner comes immediately to mind -- Nietzsche was not so vain that he wanted uncritical disciples; in fact, he explicitly said that he wanted none such. See, for example, the motto to the 2nd edition of the Froehlichen Wissenschaft.