[ajuc]

By now we've been doing

    for (int i=0; i<13; i++) {
       whatever(array[i]);
    }

    and

    def printHello():
       print("hello world"[0:5])

for decades. No point vastly messing up consistency for minimal gain. BTW notice how in both cases we count to n elements despite using 0..n-1 indexing. You don't, in fact - need to put 12 anywhere if you mean 13 elements.

[jacknews]

But

  whatever[1]

gives the second item, and the last item, of 13, is

  whatever[12]

fortran has been 1-based since well before these examples.

The point is there is no one true way, it's a trade-off.