I don't think they're all signing up just saying 'hey let's try something new!' with this neuralink. I read that it was hoped to be a mechanism for fixing some brain disorders and that's what I suspect is attracting a number of these 'thousands' to the process. If you have some sort of dread disease or terminal diagnosis and neurlink just might be able to make a positive difference in your life expectancy and quality of life (Huntington's disease?), then why wouldn't you try it?