Otherwise it's the same mentality of "why wash my ass, it's just gonna get dirty again". Even if there is no concrete finish line, since there is always room for improvement, I say improve til the point you're proud to show others what you've done and are willing to stake your name and reputation on your work.
Some of my pieces I feel like "this is me, this is the best I can do with the resources I have, one day I may become a better writer, but right now this is the best of Ms. Morgan". And there are other pieces I feel, "uh...we're going to put this in the drawer here, close it, lock it, and leave instructions for the pages to be burned upon my death." So to me it's not all the same, there is SOMETHING to strive for, even if it's not perfection.