Every stripper and/or prostitute, the story goes, plans on quitting once they make enough money to go to school/open that greasy spoon/move somewhere else.
In reality they end up `quitting' when the system is done with them and tosses them out.
9-5ers often live out the same lie.
You talk about rational choices, but what normally happens when someone has a comfortable, non-challenging job is that they start to compensate for missed excitement by filling their life with expensive habits (whether it's drugs, addiction to games and electronics, expensive cars, the cottage, etc). Soon they are completely bound to their job, those golden-handcuffs demolishing any potential they might have had.
Anyways, I've got to go off and look at a new car. My current one is 2 years old and is getting a little embarrassing.