Now what's going on here when they look into the future? I think that Honor sums it up best:
The figure didn’t answerimmediately. Then he said, “You’re probably wondering if this is a vision ofthe future.”
The figure squinted at the horizon. “I cannot see the future completely. Cultivation, she is better at it than I. It’s as if the future is a shattering window. The further you look, the more pieces that window breaks into. The near future can be anticipated, but the distant future . . . I can only guess.”
This theory is based heavily on three facts:
1. A Shardholder's interpretation of an Intent helps determine the effects on the Shardholder.
2. Cultivation is better at future sight than Honor is. (The end of Way of Kings)
3. Preservation seems to be better at future sight than Ruin is. (The prophecies)
So, I'll dive right into it.
The ability to see into the future is determined by a Shardholder's Intent. The more an Intent would look to the future, the better the Shardbearer would be at seeing the future.
It makes sense that Honor isn't as good at future sight as Cultivation is. Honor, as an emotion, tends to look at what the honorable thing to do right now is, or remembering promises that were said before to try and keep them. Cultivation is all about helping you grow in the future. So it makes sense that she would be better at future sight than Honor.
Although I don't think that this is so much because of what the Intent is, as it is the effect on the Shardholder's mind. So Cultivation isn't good at future sight because she's Cultivation- she's good at future sight because her mind is so shaped by Cultivation that it is easier to plan and see into the future. Does that make sense?
In other words, If someone ascended as Cultivation, but deeply believed that Cultivation was about learning from your past, than that Cultivation wouldn't be as good at seeing into the future.
This may explain why Preservation was so amazingly accurate with his prophecies, while Ruin managed to walk in seemingly blindly. It makes sense that Preservation would be very concerned with the long haul, while Ruin tends to be very passionate about the now, about what he can do now to destroy.
That's not to say that Ruin doesn't plan- he does a magnificent job helping overthrow The Lord Ruler. But Ati seems to have become a being of passion, of lust after Ruin. Such people don't look into their future plans very often.
Feel free to come up with more examples, or give me reasons why this doesn't work.