I disagree that it is completely unpredictable. If it is a read operation, dereferencing an invalid pointer on every normal system will either return data with an unspecified value or will raise a low level exception that may be caught.
Since a compiler cannot predict in all cases in advance whether a pointer is invalid it should be required to compile a pointer dereference the same way in all cases, i.e. emit the same code regardless of whether it has determined the pointer is invalid or not. Otherwise it effectively emits random code depending on how the optimizer is feeling.
Non-deterministic behavior for the same operation on the same values in the same program is not very helpful behavior, whenever and to the degree it can be avoided.
Since a compiler cannot predict in all cases in advance whether a pointer is invalid it should be required to compile a pointer dereference the same way in all cases, i.e. emit the same code regardless of whether it has determined the pointer is invalid or not. Otherwise it effectively emits random code depending on how the optimizer is feeling.
Non-deterministic behavior for the same operation on the same values in the same program is not very helpful behavior, whenever and to the degree it can be avoided.