Negative ROI means you end up paying for the privilege of having your job vs not having the degree at all.
A negative ROI bachelor means you could work as a cashier and earn more in net than someone who gets an expensive degree and a job that is not paying enough to offset the student loan.
A negative return master means that you would earn more in net if you stopped studying after your bachelor. In other words, you are sacrificing your bachelor earnings edge to get a masters, which is why it is more common for a master to have a negative ROI. You're already "rich" after the bachelor.
A negative ROI bachelor means you could work as a cashier and earn more in net than someone who gets an expensive degree and a job that is not paying enough to offset the student loan.
A negative return master means that you would earn more in net if you stopped studying after your bachelor. In other words, you are sacrificing your bachelor earnings edge to get a masters, which is why it is more common for a master to have a negative ROI. You're already "rich" after the bachelor.