This is slower than the current system because column 2 can not stand up (or prepare to exit) until others have completely exited. Also you cannot exit with th

This is slower than the current system because column 2 can not stand up (or prepare to exit) until others have completely exited. Also you cannot exit with the people you sit next too (like your toddler who will have to make their own way off?). And that's assuming anyone actually wants to minimise average time. Airlines don't. Neither do most passengers.