It's the definition of stupidity. Create something, and then live in pure anxiety about the creation. It doesn't mean his wrong, but it seems like a really stupid thing to have done.
AFAIK he didn't expect this will develop that fast. The biggest issue is not that technology is dangerous but that we develop it a break-the-neck speed.
We talk about human intelligence a lot, but we don't talk about human stupidity near enough.
I don't really hold a grudge, I just think he's done it, running around yelling about it probably is going to change anything. The psychopaths runs the show now.
He introduced the tech and right now, it's looking extremely unlikely anyone is going to slow down because of anything he says.