Eh, I think in a thread about org-mode that's an appropriate level of Stallman-ness.

Why?

Let me guess: because it is proprietary, has a terrible license management experience and there is an open source alternative: https://www.gnu.org/software/octave/

If Octave were sufficient for me, I think I’d just use SciPy. But I want to use LiveScripts and several other things.

I was going to say because it starts array indexes at 1.

Most "scientific" languages have indexes starting in 1 and/or configurable (R, Julia, Fortran, APL). In some applications (finite element methods), it makes sense for indexes to start at negative numbers.

Indexes starting at 1 is good. Offsets starting at 0 is good. Confusing offsets for indexes leads to off-by-one errors. C's "array" notation is taught as being an index, when it's actually an offset.