There is a fundamental difference between what causes military crashes and what causes civilian aircraft crashes. A parachute, as in WWII, or ejection seat can help the crew of a military aircraft that is disabled in flight.
In contrast, civilian aircraft are rarely disabled in flight. They have in-flight collisions or hit the ground (e.g., stall-spin at low altitude). Neither scenario allows survival with a parachute. Additionally, for light aircraft, running out of fuel is another big contributor, but in that situation, I would take my chances with an off-field landing rather than parachuting.
John