On the other hand, when you have multiple different users..
One of them sometimes suffers a crash that also loses all their work, and it really pisses them off. That's got to be bad, right? I'd like to call it severe based on its impact to that user.
But then the vast majority of your users have never seen that bug, and the bug is damn difficult to track down, so maybe you can't treat it like a stopper.
Then you are back classifying it by impact x probability... What is a different set of dimensions and make much more sense to use basically because filling those 2 dimensions tends to be easier than filling a severity dimension.
But that says nothing about why one would want 2 unrelated priority dimensions.
One of them sometimes suffers a crash that also loses all their work, and it really pisses them off. That's got to be bad, right? I'd like to call it severe based on its impact to that user.
But then the vast majority of your users have never seen that bug, and the bug is damn difficult to track down, so maybe you can't treat it like a stopper.