The answer to your question is obvious and not relevant. I don't ride on roads where anyone goes near 80 mph, so I do think that the grille guards will contribute to lethality in my case.

Given that I live in central Austin, I find it hard to believe that most drivers I encounter with grille guards need them because they have a ranch. That would imply that many more people have ranches than I believe is true. Plus, I grew up in a rural area outside of Texas and rarely saw grille guards, even on farms.