I might be a start-up owner who's convinced that the world desperately needs another social networking site. Just because I think that's an important thing for me to be working on doesn't mean that it actually is to the rest of the world. Equally, just because some people think that working on this singularity stuff is vitally important, doesn't make it so. So in short, I disagree, I don't think causation has much to do with it.
It seems incredibly irresponsible to think something is vitally important and not be working on it. Causation should have much to do with it.
It may be reasonable to think some other task is more important than this one, or for there is no task which you can identify as the most important, but it is in no way arrogant from someone to conclude that there is a most important task, or that some particular task is it, even by a large margin.
I mean, is the counterargument that there is no most important task? or that we can't know it? Or that it's arrogant to think we have it right?
You're inverting the causation. They're working on it because they think it's important, not vice-versa.