On the highway that is often enough true. I wear a full-face helmet not so much to prevent head injury as to protect my face and eyes- a bug at 80km/h is mighty painful and can make you wipe out.
Agreed. As I drive down I80 in Nebraska at 75-80 MPH I often see helmetless bike riders. The way the bugs are hitting my windshield, I cannot imagine how the bikers can stand the pelting on their faces. I would think a nectar-filled bumblebee at 80 MPH would not feel very good.