I don't camp in grizzly country, just much less dangerous Sierra black bear country.
I just started camping in a tarp and find it puts my mind much more at ease under a tarp as opposed to being in a tent.
With a tarp, when something goes bump in the night, I can just look around and see it's nothing. With a tent, I can't see through the walls since I lost my super powers, so I'm left to wonder if it's a bear, or just my imagination.
But I'm dealing with black bears, which just want our food and are generally skittish around people otherwise. That being the case, I figure if they can see me (which they can't in a tent) maybe they'll be less likely to approach, though I have no evidence for this.