Since the tool is available for Python 2 and 3, it makes sense. It's a shell tool, not a programming tool. You want to have the same behavior as much as possible everywhere, and not have to think about which Python you are using right now. Any system other than windows will likely have several versions of Python installed.

Plus, it's easier to type // to get the old behavior than it would be to type from operator import truediv to get the new behavior otherwise.