Emergency Exit Row Please

So as stated before, the movie theaters are genius here in australia. When you buy your ticket, you choose your seat on a computer, kinda like you are picking seats for a plane. Why can't America do this? It's just so simple, they make us seem like complete idiots. This way, you know ahead of time if the theater is too full, if you can't sit together, maybe even if there is a poorly placed railing on the stairs. No more waiting in line for three hours for a seat just to watch New Moon...not that i've done that.