Yes, engaging in terrorism would be too much for most signers in the list, but the point is more that there is a wide gap between what they're saying and what they're doing. You make another good point that at the very least, they should be putting their money where they mouth is.

Anthropic seem to be competing against OpenAI? And getting funds from Google? So they would probably benefit economically from delaying development, since they are currently behind. Personally I think it's more important to look at what people are doing, than just listening to what they say, as there is a strong tendency to posturing.