The software in my microwave oven, coffee maker, thermostat, DVD player, stereo receiver, and many processors in my car (including engine control, antilock brakes, and many others) is quite definitely finished.  That's not to say that there aren't any bugs, but the vendors aren't sending me any updated versions.  That's an existence proof that software *can* be "good enough" and not need updates.  Granted, most software is not "good enough", but the lack of updates to a piece of software is not sufficient to establish a priori that the software should be discarded.