> since the first element of an array is zero distance away from the beginning of the array.

That's much less of a win in any language but C, where "array" means something more than "pointer." If you're checking array bounds on every access then the extra assembler instruction to subtract one from your index doesn't matter in comparison, whereas if you're just dereferencing a pointer it could potentially double the cost of array accesses (two instructions instead of one if your instruction set has base + offset addressing modes).