Re: Disagree with this
I would consider that to be maintenance - you're not adding features, just keeping the ones you do have working.
I agree that some software can be finished - it's usually pretty obvious when you've finished writing a library or a utility application because you can't think of anything else it could do that would be both useful and relevant. On the other hand big software applications like word processors have an ever growing list of features they need to support if they want to stay competitive. There eventually comes a point where you haven't finished adding the last feature before the next one gets added to the list, and at that point you'll never finish the software.