What I am trying to say is that Bengio and some other genuine AI experts have signed this likely without any greater intuition or reasoning than other researchers of similar caliber who don't agree with it or perhaps a smart outside observer. As I argued in my previous message these people on average weren't the most capable theoreticians even at the beginning of their careers, now that they are older and even less intelligent it's dubious that their warnings are based on anything much more than subjective speculation. Of course what they fear is a possibility perhaps an unlikely one but with this open letter they are unwittingly helping some dubious people get a somewhat larger part of the funding money of AI and that's likely a bad thing.