[unpopular comment removed]
e: for what it's worth I thought it was a reasonable discussion point, not sure why you got downvoted on that one :(
Similar things are done when doing anonymous 360 surveys in the workplace. If not enough people in a certain pool respond, the feedback doesn't get shared.
Also I have enough savings and my skills are in demand enough that I wouldn’t consider signing such a letter much of a risk. The researchers at openAI are likely a good deal more in demand than I am.