There is no drive to break convention. There is only the drive to Do It Right this time, which incidentally breaks convention where convention is suboptimal. But all other things being equal, we'll still pick the conventional solution, or something close to it. Often, however, there are several conflicting conventions to pick from.

In this case, leading zero meaning octal is originally only a Unix convention, not a computerdom convention, and it's a bad convention because the Real World uses leading zeroes on decimal numbers all the time. Why just this morning my daughter was pissed off at a Web form that required her to specify the month as 09 rather than 9. Stupid, but that's the way the Real World thinks...