After years of cycling, I've gotten pretty good at tucking and rolling while flying off a bicycle, however, it really depends on how the bike ejects you. Sometimes things happen too quickly, or at a bad trajectory.

I had a front brake malfunction (1968 style center pulls) where the brake arm snapped and jammed the wheel. It launched me directly into an unexpected superman maneuver over the drops and into a parking lot. Tuck and roll was not an option, but putting my hands out to protect my face was! I didn't have gloves. I eventually healed but it hurt pretty bad for a while, so I wear gloves now.

I also find having the padding under my palms absorbs a bit of road vibration, and mine (the gloves...) have a soft fuzzy part that work well for wiping the sweat off my face on a hard ride/hot day.