In https://news.ycombinator.com/item?id=17938318 some of the parties involved mentioned that they disassociated from the paper in fear of being ostracized.

Scientists are people too. You often see people hiding their real beliefs due to the fear of retaliation and public perception as well as misinterpretation regarding controversial topics, it is only natural that scientists have the same fear, especially when considering this case where we have a highly political topic.