You don't tell which batch processor you use, so I can't check the manual, but let me guess the reason.

As you, as a programmer, knows: 074 (octal) = 60 (decimal). So if that particular batch processor happens to have the rule that numbers starting with zeroes are octal numbers, and numbers starting with 1 to 9 are decimal numbers, that neatly explains why the batch only loops to 60, not to 74: because you programmed it like that!

Moreover, I wouldn't call it 'abort'. Abort, as you know as a programmer also, generally means stopping because of an error (and usually explaining it with an error code or error message). This seems to be just a regular stop because it's ready.

Kees