Is it that hard to believe? As far as I can tell, the probability of receiving death threats approaches 1 as the size of your audience increases, and AI is a highly emotionally charged topic. Now, credible death threats are a different, much trickier question.

Yes, it's quite hard to believe. That's why one single example is sufficient for me. Then I'll be happy to extrapolate that one example to many more so it is a low bar I would say, given the OPs statement about how common this is. Note the 'easily'.

You can believe one thing or another, but the question is whether it's true. Do you sincerely not understand the difference?