That the reference can be null is hardly the fault of the implementation of Option in Java,unless people expect individual classes to modify the type system.
What the author call "black magic" I call abstraction. Why would you need to know at all times what summation and multiplications of what rows and columns are going on in your matrices? That's why use matrices, to not have to think about those all the time.
I'm not sure how those are supposed to be more human-oriented? I'll grant you "where" might be a slight improvement over "filter", but calling "map" "select"? I can't make sense of that even knowing what it's supposed to mean. If anything I'd assume it to be yet another synonym for filter.