There's more to life than a job as well. I've stayed at a job for the comfort of not needing to add to my or my families plate while my wife was in grad school. It was absolutely the right choice.

I've also had a job that I left because I wasn't enjoying because of a lack of challenge and lack of management backing for the projects I was working on.

Life isn't purely black and white and my reasoning is pretty simplistic. There are vastly more complex situations than just my wife went to grad school.