Why are catapults limited to aircraft carriers only?

The other answers here have done an excellent job of explaining why a catapult isn't used at airports: neither commercial aircraft nor passengers are built for catapult launches. read more

For an aircraft to be able to land on an aircraft carrier, meaning it can be launched by the catapult and stopped by an arresting gear, it has to be seriously beefed up. It's landing gear has to be much stronger. Also landing and being launched by catapult wears the aircraft down, it stresses it's airframe significantly. read more

Steam catapults used steam pressure to launch a piston which pulled the cable, but steam pressure takes time to build up, so it limited how fast a carrier could put planes into the sky. In the electromagnetic catapult, the cable hooks onto the plane on one end, and onto a slider with the other end. read more