I don't hand in my resignation letter without having another job offer from somewhere else. My hubby told me that his grandfather always told him that you don't quit one job until you have another job somewhere else to go to.
I feel if you are feeling unsafe in your workplace, and your boss is doing nothing to improve safety, or your job is causing you to have health problems like very bad back pain, and mental problems, or affecting your school work, it can be a good idea to leave your job.
Sometimes, the work time does not work for your schedule with college courses, other jobs if you work at another job, and other important commitments, so resigning from your job maybe a good idea.
People who have a wife and husband in the Army sometimes need to resign from their job without another offer when they need to move in a different country or place with their partner.