Why Don't Spren Appear in ________?

I've been rereading The Way of Kings and have gotten to the first Rysn interlude. In it, she wonders why the grass and leaves don't react to movement. She also mentions that she doesn't see any Spren there.

Now, if I know Sanderson, this isn't some little throw-away detail.

Why Shinovar of all places? Isn't this the country that holds the Honerblades? If anything, shouldn't they have the strongest Connection to the spren? Next to the Singers, at least.

Now, you could say that since the highstorms aren't as strong in Shinovar, neither are the spren. But that brings along the implication that since Shinovar is where Everstorm enters, would that mean that Fused activity is strongest in Shinovar? Are the Unmade also congregating in Shinovar? Would they be stronger there?

Has anything been mentioned about this in later books that I'm forgetting? Or am I grasping at something that isn't there?

These are very interesting questions, I think. Ones that might be answered soon, with the Shinovar trip in the next book.