Edit: sorry for being needlessly combative.

> Very small kids have diapers. Planes have bathrooms.

I have a 5 and 9 year old and fly regularly. I don't know if you've considered the amount of time that can elapse from seat belt sign on for landing to deplaning. Nevermind a turbulent flight.

And trying to use the bathroom at the rear of a plane that just arrived isn't really going to smooth the deplaning process.

But like I said, my family is not slowing anyone down, we're usually faster because we're ready and the adults organized the kids while we waited for our turn.

Access to the plane bathrooms is barely sufficient for me. Too much of the flight you cant get up or vc ant get to them. I've had many a flight involve my own pee pee dance, I think it is fair to say I can be a problem for some families.

We debark trains a lot with my family, and I prefer waiting, but that extra minute can be a lot easier to handle waiting in line with a three year old than sitting down. Every situation is different with people, families are included in that.