I think you might have good intentions with this question, but it seem a bit silly. You could ask the same question to anyone about any job. Why do you think the millions of investment bankers or consultants or lawyers or medical residents work long hours? Why do people work long hours in shitty retail or food service jobs? Why do people work in sweat shops? Not everyone has the opportunity to work somewhere they "enjoy more", but they keep working anyway because at the end of the day we all need a paycheck.
>Why not find a similar role at a place you enjoyed more?
That's precisely what I'm trying to do now. If you mean "why didn't you find a similar enjoyable role to begin with?", because those enjoyable roles don't pay nearly as much, and I wanted to build up a decent-sized savings so that I could take time off, travel, and work on side projects. My "plan" was to spend a few years working hard, build up a nest egg and a resume, and then transition into something more "enjoyable" though lower paying. The first part of that plan went swimmingly, but the transition part has been a little rocky.