I just thought it was because it was such a huge nexus point that their limited prescience could not see past it.Omphalos wrote:I always thought it was either the worms or the spice (and a lack of "weather" satellites), but that idea is pretty interesting too.
I also think that the fact of the observer affecting/changing the observed was mentioned (more quantum physics).
They saw enough to realize that this situation could have huge consequences for them, so they were afraid to look too deeply and risk changing the outcome badly.