This is entirely in line with the APL tradition. I suspect part of the motivation is that APL has a lot of binary operators, none of which have a conventional i

This is entirely in line with the APL tradition. I suspect part of the motivation is that APL has a lot of binary operators, none of which have a conventional infix form in traditional mathematics or anywhere else. (Cf also the Smalltalk tradition, which associates all “binary messages” to the left, but that has the motivation of allowing user-defined names without fixity declarations.)