Is there any data suggesting most med students haven't had a job or is that just a stereotype? The average age of an incoming med student is 24-25, so I'm going to call a bs on that claim. Most med students have had jobs.
Anyways, I worked 14hr day 5-6 days a week for 2 yrs. I still get tired out by this 6 day a week IM rotation. I always need to worry about my future and residency apps. I'm either in the hospital or studying and it is very isolating. When I worked 14hrs days, my time off was my own and there were no other responsibilities to manage, I had money, and all I had to worry about at work was getting things done and improving over time. Yes, there are much worse things in the world than med school, but there are still valid reasons to complain
Edit:
In an 8-Hour Day, the Average Worker Is Productive for This Many Hours Medicine/nursing/MS3 are amongst the jobs where you always have stuff to do, are always working during the day, so even if you worked prior jobs, medicine is a new experience for many. Hell, I think if you took most non-clinical med school admins and had them work the schedule of a resident they would be complaining