+1 for allowing bytes hashing. As Antoine noted, the 1D bytes variant of memoryview() fills the role previously handled by buffer().

+1 for allowing 1D non-contiguous hashing. This is from a simplicity perspective, as I don't want to have to explain to people why "hash(memoryview(b'12'[::2]))", "hash(memoryview(b'123'[::2]))" and "hash(memoryview(b'12')[::2])" all work, but "hash(memoryview(b'123')[::2])" fails.

-1 for allowing hashing when ndim > 1. We don't have a solid use case, and there's no odd value based corner cases to be considered.