Nowadays, it's considered bad form to map anything at 0... you now know one of the reasons why!
In the case that I know that has a 1:1 identity mapping of the address space, the physical address space doesn't actually have anything at 0 either, so it still doesn't need to be mapped.
In the case that I know that has a 1:1 identity mapping of the address space, the physical address space doesn't actually have anything at 0 either, so it still doesn't need to be mapped.