There are some major differences between commercial airplanes and military jets and other military and government aircraft. Due to the uses for these aircrafts, there are different parts to them. Military aircrafts are used primarily for offensive and defensive tasks during battles. The pilots would often need to eject because these aircrafts would come into danger far more often than a regular commercial jet.
Commercial jets rarely crash even though it seems like they do. Also, if a pilot ejects out of a commercial jet, then there is no way to land the aircraft safely. Sometimes, jets can be landed safely without killing all of the passengers. If the pilot has already ejected, then the pilot can’t land the plane at all because the plane will fall straight down to the ground most likely killing all on board.